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* flex_array: add helpers to get and put to make pointers easy to useEric Paris2010-08-091-0/+5
| | | | | | | | | | | | | | | | | Getting and putting arrays of pointers with flex arrays is a PITA. You have to remember to pass &ptr to the _put and you have to do weird and wacky casting to get the ptr back from the _get. Add two functions flex_array_get_ptr() and flex_array_put_ptr() to handle all of the magic. [akpm@linux-foundation.org: simplification suggested by Joe] Signed-off-by: Eric Paris <eparis@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Joe Perches <joe@perches.com> Cc: James Morris <jmorris@namei.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* iommu: inline iommu_num_pagesAnton Blanchard2010-08-091-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A profile of a network benchmark showed iommu_num_pages rather high up: 0.52% iommu_num_pages Looking at the profile, an integer divide is taking almost all of the time: % : c000000000376ea4 <.iommu_num_pages>: 1.93 : c000000000376ea4: fb e1 ff f8 std r31,-8(r1) 0.00 : c000000000376ea8: f8 21 ff c1 stdu r1,-64(r1) 0.00 : c000000000376eac: 7c 3f 0b 78 mr r31,r1 3.86 : c000000000376eb0: 38 84 ff ff addi r4,r4,-1 0.00 : c000000000376eb4: 38 05 ff ff addi r0,r5,-1 0.00 : c000000000376eb8: 7c 84 2a 14 add r4,r4,r5 46.95 : c000000000376ebc: 7c 00 18 38 and r0,r0,r3 45.66 : c000000000376ec0: 7c 84 02 14 add r4,r4,r0 0.00 : c000000000376ec4: 7c 64 2b 92 divdu r3,r4,r5 0.00 : c000000000376ec8: 38 3f 00 40 addi r1,r31,64 0.00 : c000000000376ecc: eb e1 ff f8 ld r31,-8(r1) 1.61 : c000000000376ed0: 4e 80 00 20 blr Since every caller of iommu_num_pages passes in a constant power of two we can inline this such that the divide is replaced by a shift. The entire function is only a few instructions once optimised, so it is a good candidate for inlining overall. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel.h: remove unused NIPQUAD and NIPQUAD_FMTJoe Perches2010-08-091-11/+0
| | | | | | | | | There are no more uses of NIPQUAD or NIPQUAD_FMT. Remove the definitions. Signed-off-by: Joe Perches <joe@perches.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include/linux/compiler-gcc.h: use __same_type() in __must_be_array()Rusty Russell2010-08-091-2/+1
| | | | | | | | | We should use the __same_type() helper in __must_be_array(). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpuidle: extend cpuidle and menu governor to handle dynamic statesAi Li2010-08-091-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On some SoC chips, HW resources may be in use during any particular idle period. As a consequence, the cpuidle states that the SoC is safe to enter can change from idle period to idle period. In addition, the latency and threshold of each cpuidle state can vary, depending on the operating condition when the CPU becomes idle, e.g. the current cpu frequency, the current state of the HW blocks, etc. cpuidle core and the menu governor, in the current form, are geared towards cpuidle states that are static, i.e. the availabiltiy of the states, their latencies, their thresholds are non-changing during run time. cpuidle does not provide any hook that cpuidle drivers can use to adjust those values on the fly for the current idle period before the menu governor selects the target cpuidle state. This patch extends cpuidle core and the menu governor to handle states that are dynamic. There are three additions in the patch and the patch maintains backwards-compatibility with existing cpuidle drivers. 1) add prepare() to struct cpuidle_device. A cpuidle driver can hook into the callback and cpuidle will call prepare() before calling the governor's select function. The callback gives the cpuidle driver a chance to update the dynamic information of the cpuidle states for the current idle period, e.g. state availability, latencies, thresholds, power values, etc. 2) add CPUIDLE_FLAG_IGNORE as one of the state flags. In the prepare() function, a cpuidle driver can set/clear the flag to indicate to the menu governor whether a cpuidle state should be ignored, i.e. not available, during the current idle period. 3) add power_specified bit to struct cpuidle_device. The menu governor currently assumes that the cpuidle states are arranged in the order of increasing latency, threshold, and power savings. This is true or can be made true for static states. Once the state parameters are dynamic, the latencies, thresholds, and power savings for the cpuidle states can increase or decrease by different amounts from idle period to idle period. So the assumption of increasing latency, threshold, and power savings from Cn to C(n+1) can no longer be guaranteed. It can be straightforward to calculate the power consumption of each available state and to specify it in power_usage for the idle period. Using the power_usage fields, the menu governor then selects the state that has the lowest power consumption and that still satisfies all other critieria. The power_specified bit defaults to 0. For existing cpuidle drivers, cpuidle detects that power_specified is 0 and fills in a dummy set of power_usage values. Signed-off-by: Ai Li <aili@codeaurora.org> Cc: Len Brown <len.brown@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hibernation: freeze swap at hibernationKAMEZAWA Hiroyuki2010-08-091-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | When taking a memory snapshot in hibernate_snapshot(), all (directly called) memory allocations use GFP_ATOMIC. Hence swap misusage during hibernation never occurs. But from a pessimistic point of view, there is no guarantee that no page allcation has __GFP_WAIT. It is better to have a global indication "we enter hibernation, don't use swap!". This patch tries to freeze new-swap-allocation during hibernation. (All user processes are frozenm so swapin is not a concern). This way, no updates will happen to swap_map[] between hibernate_snapshot() and save_image(). Swap is thawed when swsusp_free() is called. We can be assured that swap corruption will not occur. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ondrej Zary <linux@rainbow-software.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rmap: add exclusive page to private anon_vma on swapinRik van Riel2010-08-091-0/+2
| | | | | | | | | | | | | | | On swapin it is fairly common for a page to be owned exclusively by one process. In that case we want to add the page to the anon_vma of that process's VMA, instead of to the root anon_vma. This will reduce the amount of rmap searching that the swapout code needs to do. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: deprecate oom_adj tunableDavid Rientjes2010-08-091-0/+3
| | | | | | | | | | | | | | | | | | /proc/pid/oom_adj is now deprecated so that that it may eventually be removed. The target date for removal is August 2012. A warning will be printed to the kernel log if a task attempts to use this interface. Future warning will be suppressed until the kernel is rebooted to prevent spamming the kernel log. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: badness heuristic rewriteDavid Rientjes2010-08-093-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This a complete rewrite of the oom killer's badness() heuristic which is used to determine which task to kill in oom conditions. The goal is to make it as simple and predictable as possible so the results are better understood and we end up killing the task which will lead to the most memory freeing while still respecting the fine-tuning from userspace. Instead of basing the heuristic on mm->total_vm for each task, the task's rss and swap space is used instead. This is a better indication of the amount of memory that will be freeable if the oom killed task is chosen and subsequently exits. This helps specifically in cases where KDE or GNOME is chosen for oom kill on desktop systems instead of a memory hogging task. The baseline for the heuristic is a proportion of memory that each task is currently using in memory plus swap compared to the amount of "allowable" memory. "Allowable," in this sense, means the system-wide resources for unconstrained oom conditions, the set of mempolicy nodes, the mems attached to current's cpuset, or a memory controller's limit. The proportion is given on a scale of 0 (never kill) to 1000 (always kill), roughly meaning that if a task has a badness() score of 500 that the task consumes approximately 50% of allowable memory resident in RAM or in swap space. The proportion is always relative to the amount of "allowable" memory and not the total amount of RAM systemwide so that mempolicies and cpusets may operate in isolation; they shall not need to know the true size of the machine on which they are running if they are bound to a specific set of nodes or mems, respectively. Root tasks are given 3% extra memory just like __vm_enough_memory() provides in LSMs. In the event of two tasks consuming similar amounts of memory, it is generally better to save root's task. Because of the change in the badness() heuristic's baseline, it is also necessary to introduce a new user interface to tune it. It's not possible to redefine the meaning of /proc/pid/oom_adj with a new scale since the ABI cannot be changed for backward compatability. Instead, a new tunable, /proc/pid/oom_score_adj, is added that ranges from -1000 to +1000. It may be used to polarize the heuristic such that certain tasks are never considered for oom kill while others may always be considered. The value is added directly into the badness() score so a value of -500, for example, means to discount 50% of its memory consumption in comparison to other tasks either on the system, bound to the mempolicy, in the cpuset, or sharing the same memory controller. /proc/pid/oom_adj is changed so that its meaning is rescaled into the units used by /proc/pid/oom_score_adj, and vice versa. Changing one of these per-task tunables will rescale the value of the other to an equivalent meaning. Although /proc/pid/oom_adj was originally defined as a bitshift on the badness score, it now shares the same linear growth as /proc/pid/oom_score_adj but with different granularity. This is required so the ABI is not broken with userspace applications and allows oom_adj to be deprecated for future removal. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: move badness() declaration into oom.hAndrew Morton2010-08-091-0/+6
| | | | | | | | | Cc: Minchan Kim <minchan.kim@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmscan: kill prev_priority completelyKOSAKI Motohiro2010-08-092-20/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since 2.6.28 zone->prev_priority is unused. Then it can be removed safely. It reduce stack usage slightly. Now I have to say that I'm sorry. 2 years ago, I thought prev_priority can be integrate again, it's useful. but four (or more) times trying haven't got good performance number. Thus I give up such approach. The rest of this changelog is notes on prev_priority and why it existed in the first place and why it might be not necessary any more. This information is based heavily on discussions between Andrew Morton, Rik van Riel and Kosaki Motohiro who is heavily quotes from. Historically prev_priority was important because it determined when the VM would start unmapping PTE pages. i.e. there are no balances of note within the VM, Anon vs File and Mapped vs Unmapped. Without prev_priority, there is a potential risk of unnecessarily increasing minor faults as a large amount of read activity of use-once pages could push mapped pages to the end of the LRU and get unmapped. There is no proof this is still a problem but currently it is not considered to be. Active files are not deactivated if the active file list is smaller than the inactive list reducing the liklihood that file-mapped pages are being pushed off the LRU and referenced executable pages are kept on the active list to avoid them getting pushed out by read activity. Even if it is a problem, prev_priority prev_priority wouldn't works nowadays. First of all, current vmscan still a lot of UP centric code. it expose some weakness on some dozens CPUs machine. I think we need more and more improvement. The problem is, current vmscan mix up per-system-pressure, per-zone-pressure and per-task-pressure a bit. example, prev_priority try to boost priority to other concurrent priority. but if the another task have mempolicy restriction, it is unnecessary, but also makes wrong big latency and exceeding reclaim. per-task based priority + prev_priority adjustment make the emulation of per-system pressure. but it have two issue 1) too rough and brutal emulation 2) we need per-zone pressure, not per-system. Another example, currently DEF_PRIORITY is 12. it mean the lru rotate about 2 cycle (1/4096 + 1/2048 + 1/1024 + .. + 1) before invoking OOM-Killer. but if 10,0000 thrreads enter DEF_PRIORITY reclaim at the same time, the system have higher memory pressure than priority==0 (1/4096*10,000 > 2). prev_priority can't solve such multithreads workload issue. In other word, prev_priority concept assume the sysmtem don't have lots threads." Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: implement writeback livelock avoidance using page taggingJan Kara2010-08-092-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | We try to avoid livelocks of writeback when some steadily creates dirty pages in a mapping we are writing out. For memory-cleaning writeback, using nr_to_write works reasonably well but we cannot really use it for data integrity writeback. This patch tries to solve the problem. The idea is simple: Tag all pages that should be written back with a special tag (TOWRITE) in the radix tree. This can be done rather quickly and thus livelocks should not happen in practice. Then we start doing the hard work of locking pages and sending them to disk only for those pages that have TOWRITE tag set. Note: Adding new radix tree tag grows radix tree node from 288 to 296 bytes for 32-bit archs and from 552 to 560 bytes for 64-bit archs. However, the number of slab/slub items per page remains the same (13 and 7 respectively). Signed-off-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Chris Mason <chris.mason@oracle.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* radix-tree: omplement function radix_tree_range_tag_if_taggedJan Kara2010-08-091-0/+4
| | | | | | | | | | | | | | Implement function for setting one tag if another tag is set for each item in given range. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Chris Mason <chris.mason@oracle.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ksm: fix ksm swapin time optimizationAndrea Arcangeli2010-08-091-1/+1
| | | | | | | | | | | | | | | | | | | | The new anon-vma code, was suboptimal and it lead to erratic invocation of ksm_does_need_to_copy. That leads to host hangs or guest vnc lockup, or weird behavior. It's unclear why ksm_does_need_to_copy is unstable but the point is that when KSM is not in use, ksm_does_need_to_copy must never run or we bounce pages for no good reason. I suspect the same hangs will happen with KVM swaps. But this at least fixes the regression in the new-anon-vma code and it only let KSM bugs triggers when KSM is in use. The code in do_swap_page likely doesn't cope well with a not-swapcache, especially the memcg code. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Izik Eidus <ieidus@yahoo.com> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: make tmpfs scalable with percpu_counter for used blocksTim Chen2010-08-091-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation of tmpfs is not scalable. We found that stat_lock is contended by multiple threads when we need to get a new page, leading to useless spinning inside this spin lock. This patch makes use of the percpu_counter library to maintain local count of used blocks to speed up getting and returning of pages. So the acquisition of stat_lock is unnecessary for getting and returning blocks, improving the performance of tmpfs on system with large number of cpus. On a 4 socket 32 core NHM-EX system, we saw improvement of 270%. The implementation below has a slight chance of race between threads causing a slight overshoot of the maximum configured blocks. However, any overshoot is small, and is bounded by the number of cpus. This happens when the number of used blocks is slightly below the maximum configured blocks when a thread checks the used block count, and another thread allocates the last block before the current thread does. This should not be a problem for tmpfs, as the overshoot is most likely to be a few blocks and bounded. If a strict limit is really desired, then configured the max blocks to be the limit less the number of cpus in system. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: add accurate compare function to percpu_counter libraryTim Chen2010-08-091-0/+11
| | | | | | | | | | | | | | | | | | | Add percpu_counter_compare that allows for a quick but accurate comparison of percpu_counter with a given value. A rough count is provided by the count field in percpu_counter structure, without accounting for the other values stored in individual cpu counters. The actual count is a sum of count and the cpu counters. However, count field is never different from the actual value by a factor of batch*num_online_cpu. We do not need to get actual count for comparison if count is different from the given value by this factor and allows for quick comparison without summing up all the per cpu counters. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gcc-4.6: mm: fix unused but set warningsAndi Kleen2010-08-092-2/+6
| | | | | | | | No real bugs, just some dead code and some fixups. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gcc-4.6: pagemap: avoid unused-but-set variableAndi Kleen2010-08-091-1/+3
| | | | | | | | Avoid quite a lot of warnings in header files in a gcc 4.6 -Wall builds Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* topology: alternate fix for ia64 tiger_defconfig build breakageLee Schermerhorn2010-08-091-4/+0
| | | | | | | | | | | | | | | | Define stubs for the numa_*_id() generic percpu related functions for non-NUMA configurations in <asm-generic/topology.h> where the other non-numa stubs live. Fixes ia64 !NUMA build breakage -- e.g., tiger_defconfig Back out now unneeded '#ifndef CONFIG_NUMA' guards from ia64 smpboot.c Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Tested-by: Tony Luck <tony.luck@intel.com> Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mmzone.h: remove dead prototypeAlexander Nevenchannyy2010-08-091-2/+0
| | | | | | | | | get_zone_counts() was dropped from kernel tree, see: http://www.mail-archive.com/mm-commits@vger.kernel.org/msg07313.html but its prototype remains. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: rename try_set_zone_oom() to try_set_zonelist_oom()Minchan Kim2010-08-091-1/+1
| | | | | | | | | | | | | | | | We have been used naming try_set_zone_oom and clear_zonelist_oom. The role of functions is to lock of zonelist for preventing parallel OOM. So clear_zonelist_oom makes sense but try_set_zone_oome is rather awkward and unmatched with clear_zonelist_oom. Let's change it with try_set_zonelist_oom. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: move sysctl declarations to oom.hDavid Rientjes2010-08-091-0/+5
| | | | | | | | | | | | The three oom killer sysctl variables (sysctl_oom_dump_tasks, sysctl_oom_kill_allocating_task, and sysctl_panic_on_oom) are better declared in include/linux/oom.h rather than kernel/sysctl.c. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: extract panic helper functionDavid Rientjes2010-08-091-0/+1
| | | | | | | | | | | | | | | | | There are various points in the oom killer where the kernel must determine whether to panic or not. It's better to extract this to a helper function to remove all the confusion as to its semantics. Also fix a call to dump_header() where tasklist_lock is not read- locked, as required. There's no functional change with this patch. Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: select task from tasklist for mempolicy oomsDavid Rientjes2010-08-091-1/+12
| | | | | | | | | | | | | | | | | | | The oom killer presently kills current whenever there is no more memory free or reclaimable on its mempolicy's nodes. There is no guarantee that current is a memory-hogging task or that killing it will free any substantial amount of memory, however. In such situations, it is better to scan the tasklist for nodes that are allowed to allocate on current's set of nodes and kill the task with the highest badness() score. This ensures that the most memory-hogging task, or the one configured by the user with /proc/pid/oom_adj, is always selected in such scenarios. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* buffer_head: remove redundant test from wait_on_bufferRichard Kennedy2010-08-091-6/+1
| | | | | | | | | | | | | | | | The comment suggests that when b_count equals zero it is calling __wait_no_buffer to trigger some debug, but as there is no debug in __wait_on_buffer the whole thing is redundant. AFAICT from the git log this has been the case for at least 5 years, so it seems safe just to remove this. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: extend KSM refcounts to the anon_vma rootRik van Riel2010-08-091-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | KSM reference counts can cause an anon_vma to exist after the processe it belongs to have already exited. Because the anon_vma lock now lives in the root anon_vma, we need to ensure that the root anon_vma stays around until after all the "child" anon_vmas have been freed. The obvious way to do this is to have a "child" anon_vma take a reference to the root in anon_vma_fork. When the anon_vma is freed at munmap or process exit, we drop the refcount in anon_vma_unlink and possibly free the root anon_vma. The KSM anon_vma reference count function also needs to be modified to deal with the possibility of freeing 2 levels of anon_vma. The easiest way to do this is to break out the KSM magic and make it generic. When compiling without CONFIG_KSM, this code is compiled out. Signed-off-by: Rik van Riel <riel@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: always lock the root (oldest) anon_vmaRik van Riel2010-08-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | Always (and only) lock the root (oldest) anon_vma whenever we do something in an anon_vma. The recently introduced anon_vma scalability is due to the rmap code scanning only the VMAs that need to be scanned. Many common operations still took the anon_vma lock on the root anon_vma, so always taking that lock is not expected to introduce any scalability issues. However, always taking the same lock does mean we only need to take one lock, which means rmap_walk on pages from any anon_vma in the vma is excluded from occurring during an munmap, expand_stack or other operation that needs to exclude rmap_walk and similar functions. Also add the proper locking to vma_adjust. Signed-off-by: Rik van Riel <riel@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: track the root (oldest) anon_vmaRik van Riel2010-08-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | Track the root (oldest) anon_vma in each anon_vma tree. Because we only take the lock on the root anon_vma, we cannot use the lock on higher-up anon_vmas to lock anything. This makes it impossible to do an indirect lookup of the root anon_vma, since the data structures could go away from under us. However, a direct pointer is safe because the root anon_vma is always the last one that gets freed on munmap or exit, by virtue of the same_vma list order and unlink_anon_vmas walking the list forward. [akpm@linux-foundation.org: fix typo] Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: change direct call of spin_lock(anon_vma->lock) to inline functionRik van Riel2010-08-091-0/+10
| | | | | | | | | | | | | | | | | | | | | Subsitute a direct call of spin_lock(anon_vma->lock) with an inline function doing exactly the same. This makes it easier to do the substitution to the root anon_vma lock in a following patch. We will deal with the handful of special locks (nested, dec_and_lock, etc) separately. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: rename anon_vma_lock to vma_lock_anon_vmaRik van Riel2010-08-091-2/+2
| | | | | | | | | | | | | | | | Rename anon_vma_lock to vma_lock_anon_vma. This matches the naming style used in page_lock_anon_vma and will come in really handy further down in this patch series. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kmap_atomic: make kunmap_atomic() harder to misuseCesar Eduardo Barros2010-08-091-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kunmap_atomic() is currently at level -4 on Rusty's "Hard To Misuse" list[1] ("Follow common convention and you'll get it wrong"), except in some architectures when CONFIG_DEBUG_HIGHMEM is set[2][3]. kunmap() takes a pointer to a struct page; kunmap_atomic(), however, takes takes a pointer to within the page itself. This seems to once in a while trip people up (the convention they are following is the one from kunmap()). Make it much harder to misuse, by moving it to level 9 on Rusty's list[4] ("The compiler/linker won't let you get it wrong"). This is done by refusing to build if the type of its first argument is a pointer to a struct page. The real kunmap_atomic() is renamed to kunmap_atomic_notypecheck() (which is what you would call in case for some strange reason calling it with a pointer to a struct page is not incorrect in your code). The previous version of this patch was compile tested on x86-64. [1] http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html [2] In these cases, it is at level 5, "Do it right or it will always break at runtime." [3] At least mips and powerpc look very similar, and sparc also seems to share a common ancestor with both; there seems to be quite some degree of copy-and-paste coding here. The include/asm/highmem.h file for these three archs mention x86 CPUs at its top. [4] http://ozlabs.org/~rusty/index.cgi/tech/2008-03-30.html [5] As an aside, could someone tell me why mn10300 uses unsigned long as the first parameter of kunmap_atomic() instead of void *? Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Cc: Russell King <linux@arm.linux.org.uk> (arch/arm) Cc: Ralf Baechle <ralf@linux-mips.org> (arch/mips) Cc: David Howells <dhowells@redhat.com> (arch/frv, arch/mn10300) Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> (arch/mn10300) Cc: Kyle McMartin <kyle@mcmartin.ca> (arch/parisc) Cc: Helge Deller <deller@gmx.de> (arch/parisc) Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> (arch/parisc) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> (arch/powerpc) Cc: Paul Mackerras <paulus@samba.org> (arch/powerpc) Cc: "David S. Miller" <davem@davemloft.net> (arch/sparc) Cc: Thomas Gleixner <tglx@linutronix.de> (arch/x86) Cc: Ingo Molnar <mingo@redhat.com> (arch/x86) Cc: "H. Peter Anvin" <hpa@zytor.com> (arch/x86) Cc: Arnd Bergmann <arnd@arndb.de> (include/asm-generic) Cc: Rusty Russell <rusty@rustcorp.com.au> ("Hard To Misuse" list) Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds2010-08-082-12/+13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: arch/tile: check kmalloc() result arch/tile: catch up on various minor cleanups. arch/tile: avoid erroneous error return for PTRACE_POKEUSR. tile: set ARCH_KMALLOC_MINALIGN tile: remove homegrown L1_CACHE_ALIGN macro arch/tile: Miscellaneous cleanup changes. arch/tile: Split the icache flush code off to a generic <arch> header. arch/tile: Fix bug in support for atomic64_xx() ops. arch/tile: Shrink the tile-opcode files considerably. arch/tile: Add driver to enable access to the user dynamic network. arch/tile: Enable more sophisticated IRQ model for 32-bit chips. Move list types from <linux/list.h> to <linux/types.h>. Add wait4() back to the set of <asm-generic/unistd.h> syscalls. Revert adding some arch-specific signal syscalls to <linux/syscalls.h>. arch/tile: Do not use GFP_KERNEL for dma_alloc_coherent(). Feedback from fujita.tomonori@lab.ntt.co.jp. arch/tile: core support for Tilera 32-bit chips. Fix up the "generic" unistd.h ABI to be more useful.
| * Merge branch 'master' into for-linusChris Metcalf2010-08-06143-752/+3267
| |\
| * \ Merge branch 'master' into for-linusChris Metcalf2010-07-0613-29/+65
| |\ \
| * | | Move list types from <linux/list.h> to <linux/types.h>.Chris Metcalf2010-07-062-12/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows a list_head (or hlist_head, etc.) to be used from places that used to be impractical, in particular <asm/processor.h>, which used to cause include file recursion: <linux/list.h> includes <linux/prefetch.h>, which always includes <asm/processor.h> for the prefetch macros, as well as <asm/system.h>, which often includes <asm/processor.h> directly or indirectly. This avoids a lot of painful workaround hackery on the tile architecture, where we use a list_head in the thread_struct to chain together tasks that are activated on a particular hardwall. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
* | | | Merge branch 'for-linus' of git://gitorious.org/linux-omap-dss2/linuxLinus Torvalds2010-08-081-1/+4
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://gitorious.org/linux-omap-dss2/linux: (64 commits) OMAP: DSS2: OMAPFB: add support for FBIO_WAITFORVSYNC OMAP: DSS2: Replace strncmp() with sysfs_streq() in overlay_manager_store() OMAP: DSS2: Fix error path in omap_dsi_update() OMAP: DSS2: TDO35S: fix video signaling OMAP: DSS2: OMAPFB: Fix invalid bpp for PAL and NTSC modes OMAP: DSS2: OMAPFB: Fix probe error path OMAP3EVM: Replace vdvi regulator supply with vdds_dsi OMAP: DSS2: Remove extra return statement OMAP: DSS2: adjust YUV overlay width to be even OMAP: DSS2: OMAPFB: Fix sysfs mirror input check OMAP: DSS2: OMAPFB: Remove redundant color register range check OMAP: DSS2: OMAPFB: Remove redundant rotate range check OMAP: DSS2: OMAPFB: Check fb2display() return value OMAP: DSS2: Taal: Optimize enable_te, rotate, mirror when value unchanged OMAP: DSS2: DSI: detect unsupported update requests OMAP: DSS2: DSI: increase FIFO low threshold OMAP: DSS2: DSI: Add error IRQ mask for DSI complexIO OMAP: DSS2: DSI: Remove BTA after set_max_rx_packet_size OMAP: DSS2: change manual update scaling setup OMAP: DSS2: DSI: use BTA to end the frame transfer ...
| * | | | OMAP: DSS2: OMAPFB: Add support for switching memory regionsVille Syrjälä2010-08-031-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Separate the memory region from the framebuffer device a little bit. It's now possible to select the memory region used by the framebuffer device using the new mem_idx parameter of omapfb_plane_info. If the mem_idx is specified it will be interpreted as an index into the memory regions array, if it's not specified the framebuffer's index is used instead. So by default each framebuffer keeps using it's own memory region which preserves backwards compatibility. This allows cloning the same memory region to several overlays and yet each overlay can be controlled independently since they can be associated with separate framebuffer devices. Signed-off-by: Ville Syrjälä <ville.syrjala@nokia.com> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
* | | | | Merge branch 'for-linus' of ↵Linus Torvalds2010-08-072-112/+451
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: (82 commits) firewire: core: add forgotten dummy driver methods, remove unused ones firewire: add isochronous multichannel reception firewire: core: small clarifications in core-cdev firewire: core: remove unused code firewire: ohci: release channel in error path firewire: ohci: use memory barriers to order descriptor updates tools/firewire: nosy-dump: increment program version tools/firewire: nosy-dump: remove unused code tools/firewire: nosy-dump: use linux/firewire-constants.h tools/firewire: nosy-dump: break up a deeply nested function tools/firewire: nosy-dump: make some symbols static or const tools/firewire: nosy-dump: change to kernel coding style tools/firewire: nosy-dump: work around segfault in decode_fcp tools/firewire: nosy-dump: fix it on x86-64 tools/firewire: add userspace front-end of nosy firewire: nosy: note ioctls in ioctl-number.txt firewire: nosy: use generic printk macros firewire: nosy: endianess fixes and annotations firewire: nosy: annotate __user pointers and __iomem pointers firewire: nosy: fix device shutdown with active client ...
| | \ \ \ \
| | \ \ \ \
| *-. \ \ \ \ Merge firewire branches to be released post v2.6.35Stefan Richter2010-08-022-112/+451
| |\ \ \ \ \ \ | | |_|/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/firewire/core-card.c drivers/firewire/core-cdev.c and forgotten #include <linux/time.h> in drivers/firewire/ohci.c Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: add isochronous multichannel receptionStefan Richter2010-07-292-96/+214
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds the DMA context programming and userspace ABI for multichannel reception, i.e. for listening on multiple channel numbers by means of a single DMA context. The use case is reception of more streams than there are IR DMA units offered by the link layer. This is already implemented by the older ohci1394 + ieee1394 + raw1394 stack. And as discussed recently on linux1394-devel, this feature is occasionally used in practice. The big drawbacks of this mode are that buffer layout and interrupt generation necessarily differ from single-channel reception: Headers and trailers are not stripped from packets, packets are not aligned with buffer chunks, interrupts are per buffer chunk, not per packet. These drawbacks also cause a rather hefty code footprint to support this rarely used OHCI-1394 feature. (367 lines added, among them 94 lines of added userspace ABI documentation.) This implementation enforces that a multichannel reception context may only listen to channels to which no single-channel context on the same link layer is presently listening to. OHCI-1394 would allow to overlay single-channel contexts by the multi-channel context, but this would be a departure from the present first-come-first-served policy of IR context creation. The implementation is heavily based on an earlier one by Jay Fenlason. Thanks Jay. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: improve FW_CDEV_IOC_ALLOCATEStefan Richter2010-07-231-5/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In both the ieee1394 stack and the firewire stack, the core treats kernelspace drivers better than userspace drivers when it comes to CSR address range allocation: The former may request a register to be placed automatically at a free spot anywhere inside a specified address range. The latter may only request a register at a fixed offset. Hence, userspace drivers which do not require a fixed offset potentially need to implement a retry loop with incremented offset in each retry until the kernel does not fail allocation with EBUSY. This awkward procedure is not fundamentally necessary as the core already provides a superior allocation API to kernelspace drivers. Therefore change the ioctl() ABI by addition of a region_end member in the existing struct fw_cdev_allocate. Userspace and kernelspace APIs work the same way now. There is a small cost to pay by clients though: If client source code is required to compile with older kernel headers too, then any use of the new member fw_cdev_allocate.region_end needs to be enclosed by #ifdef/#endif directives. However, any client program that seriously wants to use address range allocations will require a kernel of cdev ABI version >= 4 at runtime and a linux/firewire-cdev.h header of >= 4 anyway. This is because v4 brings FW_CDEV_EVENT_REQUEST2. The only client program in which build-time compatibility with struct fw_cdev_allocate as found in older kernel headers makes sense is libraw1394. (libraw1394 uses the older broken FW_CDEV_EVENT_REQUEST to implement a makeshift, incorrect transaction responder that does at least work somewhat in many simple scenarios, relying on guesswork by libraw1394 and by libraw1394 based applications. Plus, address range allocation and transaction responder is only one of many features that libraw1394 needs to provide, and these other features need to work with kernel and kernel-headers as old as possible. Any new linux/firewire-cdev.h based client that implements a transaction responder should never attempt to do it like libraw1394; instead it should make a header and kernel of v4 or later a hard requirement.) While we are at it, update the struct fw_cdev_allocate documentation to better reflect the recent fw_cdev_event_request2 ABI addition. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: add PHY pingingStefan Richter2010-07-231-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This extends the FW_CDEV_IOC_SEND_PHY_PACKET ioctl() for /dev/fw* to be useful for ping time measurements. One application for it would be gap count optimization in userspace that is based on ping times rather than hop count. (The latter is implemented in firewire-core itself but is not applicable to beta PHYs that act as repeater.) Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: add PHY packet receptionStefan Richter2010-07-232-8/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an FW_CDEV_IOC_RECEIVE_PHY_PACKETS ioctl() and FW_CDEV_EVENT_PHY_PACKET_RECEIVED poll()/read() event for /dev/fw*. This can be used to get information from remote PHYs by remote access PHY packets. This is also the 2nd half of the functionality (the receive part) to support a userspace implementation of a VersaPHY transaction layer. Safety considerations: - PHY packets are generally broadcasts, hence some kind of elevated privileges should be required of a process to be able to listen in on PHY packets. This implementation assumes that a process that is allowed to open the /dev/fw* of a local node does have this privilege. There was an inconclusive discussion about introducing POSIX capabilities as a means to check for user privileges for these kinds of operations. Other limitations: - PHY packet reception may be switched on by ioctl() but cannot be switched off again. It would be trivial to provide an off switch, but this is not worth the code. The client should simply close() the fd then, or just ignore further events. - For sake of simplicity of API and kernel-side implementation, no filter per packet content is provided. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: add PHY packet transmissionStefan Richter2010-07-231-1/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an FW_CDEV_IOC_SEND_PHY_PACKET ioctl() for /dev/fw* which can be used to implement bus management related functionality in userspace. This is also half of the functionality (the transmit part) that is needed to support a userspace implementation of a VersaPHY transaction layer. Safety considerations: - PHY packets are generally broadcasts and may have interesting effects on PHYs and the bus, e.g. make asynchronous arbitration impossible due to too low gap count. Hence some kind of elevated privileges should be required of a process to be able to send PHY packets. This implementation assumes that a process that is allowed to open the /dev/fw* of a local node does have this privilege. There was an inconclusive discussion about introducing POSIX capabilities as a means to check for user privileges for these kinds of operations. - The kernel does not check integrity of the supplied packet data. That would be far too much code, considering the many kinds of PHY packets. A process which got the privilege to send these packets is trusted to do it correctly. Just like with the other "send packet" ioctls, a non-blocking API is chosen; i.e. the ioctl may return even before AT DMA started. After transmission, an event for poll()/read() is enqueued. Most users are going to need a blocking API, but a blocking userspace wrapper is easy to implement, and the second of the two existing libraw1394 calls raw1394_phy_packet_write() and raw1394_start_phy_packet_write() can be better supported that way. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: some clarifications to the API documentationStefan Richter2010-07-231-8/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Response events: - are generated on more occasions than their documentation claimed. CSR allocation: - An already occupied CSR can be determined from errno==EBUSY. Bus resets: - Note that FW_CDEV_IOC_INITIATE_BUS_RESET is nonblocking and that the client is not required to observe a grace period since kernels 2.6.36+ will enforce it now (commit 02d37bed). - The possible values of fw_cdev_initiate_bus_reset.type are listed in the kerneldoc comment already. - Clarify that an application that uses FW_CDEV_IOC_ADD_DESCRIPTOR and FW_CDEV_IOC_REMOVE_DESCRIPTOR does not have to issue a bus reset. Isochronous I/O contexts: - At most one can be created per open file descriptor. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: normalize status values in packet callbacksStefan Richter2010-07-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | core-transaction.c transmit_complete_callback() and close_transaction() expect packet callback status to be an ACK or RCODE, and ACKs get translated to RCODEs for transaction callbacks. An old comment on the packet callback API (been there from the initial submission of the stack) and the dummy_driver implementation of send_request/send_response deviated from this as they also included -ERRNO in the range of status values. Let's narrow status values down to ACK and RCODE to prevent surprises. RCODE_CANCELLED is chosen as the dummy_driver's RCODE as its meaning of "transaction timed out" comes closest to what happens when a transaction coincides with card removal. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: core: integrate software-forced bus resets with bus managementStefan Richter2010-07-131-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bus resets which are triggered - by the kernel drivers after updates of the local nodes' config ROM, - by userspace software via ioctl shall be deferred until after >=2 seconds after the last bus reset. If multiple modifications of the local nodes' config ROM happen in a row, only a single bus reset should happen after them. When the local node's link goes from inactive to active or vice versa, and at the two occasions of bus resets mentioned above --- and if the current gap count differs from 63 --- the bus reset should be preceded by a PHY configuration packet that reaffirms the gap count. Otherwise a bus manager would have to reset the bus again right after that. This is necessary to promote bus stability, e.g. leave grace periods for allocations and reallocations of isochronous channels and bandwidth, SBP-2 reconnections etc.; see IEEE 1394 clause 8.2.1. This change implements all of the above by moving bus reset initiation into a delayed work (except for bus resets which are triggered by the bus manager workqueue job and are performed there immediately). It comes with a necessary addition to the card driver methods that allows to get the current gap count from PHY registers. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: fix fw_cdev_event_bus_reset.bm_node_idStefan Richter2010-07-082-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix an obscure ABI feature that is a bit of a hassle to implement. However, somebody put it into the ABI, so let's fill in a sensible value there. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: extend fw_cdev_event_iso_interrupt documentationStefan Richter2010-06-201-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add information regarding the 2.6.32 update to the xmit variant of fw_cdev_event_iso_interrupt. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
| | | * | | | firewire: cdev: fix ABI for FCP and address range mapping, add ↵Stefan Richter2010-06-201-2/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fw_cdev_event_request2 The problem: A target-like userspace driver, e.g. AV/C target or SBP-2/3 target, needs to be able to act as responder and requester. In the latter role, it needs to send requests to nods from which it received requests. This is currently impossible because fw_cdev_event_request lacks information about sender node ID. Reported-by: Jay Fenlason <fenlason@redhat.com> Libffado + libraw1394 + firewire-core is currently unable to drive two or more audio devices on the same bus. Reported-by: Arnold Krille <arnold@arnoldarts.de> This is because libffado requires destination node ID of FCP requests and sender node ID of FCP responses to match. It even prohibits libffado from working with a bus on which libraw1394 opens a /dev/fw* as default ioctl device that does not correspond with the audio device. This is because libraw1394 does not receive the sender node ID from the kernel. Moreover, fw_cdev_event_request makes it impossible to tell unicast and broadcast write requests apart. The fix: Add a replacement of struct fw_cdev_event_request request, boringly called struct fw_cdev_event_request2. The new event will be sent to a userspace client instead of the old one if the client claims compatibility with <linux/firewire-cdev.h> ABI version 4 or later. libraw1394 needs to be extended to make use of the new event, in order to properly support libffado and other FCP or address range mapping users who require correct sender node IDs. Further notes: While we are at it, change back the range of possible values of fw_cdev_event_request.tcode to 0x0...0xb like in ABI version <= 3. The preceding change "firewire: expose extended tcode of incoming lock requests to (userspace) drivers" expanded it to 0x0...0x17 which could catch sloppily coded clients by surprise. The extended range of codes is only used in the new fw_cdev_event_request2.tcode. Jay and I also suggested an alternative approach to fix the ABI for incoming requests: Add an FW_CDEV_IOC_GET_REQUEST_INFO ioctl which can be called after reception of an fw_cdev_event_request, before issuing of the closing FW_CDEV_IOC_SEND_RESPONSE ioctl. The new ioctl would reveal the vital information about a request that fw_cdev_event_request lacks. Jay showed an implementation of this approach. The former event approach adds 27 LOC of rather trivial code to core-cdev.c, the ioctl approach 34 LOC, some of which is nontrivial. The ioctl approach would certainly also add more LOC to userspace programs which require the expanded information on inbound requests. This approach is probably only on the lighter-weight side in case of clients that want to be compatible with kernels that lack the new capability, like libraw1394. However, the code to be added to such libraw1394-like clients in case of the event approach is a straight- forward additional switch () case in its event handler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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