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* rcu: remove redundant ACCESS_ONCE definition from rcupreempt.cPaul E. McKenney2008-08-181-8/+0
| | | | | | | | | Remove the redundant definition of ACCESS_ONCE() from rcupreempt.c in favor of the one in compiler.h. Also merge the comment header from rcupreempt.c's definition into that in compiler.h. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: fix classic RCU locking cleanup lockdep problemPaul E. McKenney2008-08-171-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Fri, Aug 15, 2008 at 04:24:30PM +0200, Ingo Molnar wrote: > > Paul, > > one of your two recent RCU patches caused this lockdep splat in -tip > testing: > > -------------------> > Brought up 2 CPUs > Total of 2 processors activated (6850.87 BogoMIPS). > PM: Adding info for No Bus:platform > khelper used greatest stack depth: 3124 bytes left > > ================================= > [ INFO: inconsistent lock state ] > 2.6.27-rc3-tip #1 > --------------------------------- > inconsistent {softirq-on-W} -> {in-softirq-W} usage. > ksoftirqd/0/4 [HC0[0]:SC1[1]:HE1:SE0] takes: > (&rcu_ctrlblk.lock){-+..}, at: [<c016d91c>] __rcu_process_callbacks+0x1ac/0x1f0 > {softirq-on-W} state was registered at: > [<c01528e4>] __lock_acquire+0x3f4/0x5b0 > [<c0152b29>] lock_acquire+0x89/0xc0 > [<c076142b>] _spin_lock+0x3b/0x70 > [<c016d649>] rcu_init_percpu_data+0x29/0x80 > [<c075e43f>] rcu_cpu_notify+0xaf/0xd0 > [<c076458d>] notifier_call_chain+0x2d/0x60 > [<c0145ede>] __raw_notifier_call_chain+0x1e/0x30 > [<c075db29>] _cpu_up+0x79/0x110 > [<c075dc0d>] cpu_up+0x4d/0x70 > [<c0a769e1>] kernel_init+0xb1/0x200 > [<c01048a3>] kernel_thread_helper+0x7/0x10 > [<ffffffff>] 0xffffffff > irq event stamp: 14 > hardirqs last enabled at (14): [<c01534db>] trace_hardirqs_on+0xb/0x10 > hardirqs last disabled at (13): [<c014dbeb>] trace_hardirqs_off+0xb/0x10 > softirqs last enabled at (0): [<c012b186>] copy_process+0x276/0x1190 > softirqs last disabled at (11): [<c0105c0a>] call_on_stack+0x1a/0x30 > > other info that might help us debug this: > no locks held by ksoftirqd/0/4. > > stack backtrace: > Pid: 4, comm: ksoftirqd/0 Not tainted 2.6.27-rc3-tip #1 > [<c01504dc>] print_usage_bug+0x16c/0x1b0 > [<c0152455>] mark_lock+0xa75/0xb10 > [<c0108b75>] ? sched_clock+0x15/0x30 > [<c015289d>] __lock_acquire+0x3ad/0x5b0 > [<c0152b29>] lock_acquire+0x89/0xc0 > [<c016d91c>] ? __rcu_process_callbacks+0x1ac/0x1f0 > [<c076142b>] _spin_lock+0x3b/0x70 > [<c016d91c>] ? __rcu_process_callbacks+0x1ac/0x1f0 > [<c016d91c>] __rcu_process_callbacks+0x1ac/0x1f0 > [<c016d986>] rcu_process_callbacks+0x26/0x50 > [<c0132305>] __do_softirq+0x95/0x120 > [<c0132270>] ? __do_softirq+0x0/0x120 > [<c0105c0a>] call_on_stack+0x1a/0x30 > [<c0132426>] ? ksoftirqd+0x96/0x110 > [<c0132390>] ? ksoftirqd+0x0/0x110 > [<c01411f7>] ? kthread+0x47/0x80 > [<c01411b0>] ? kthread+0x0/0x80 > [<c01048a3>] ? kernel_thread_helper+0x7/0x10 > ======================= > calling init_cpufreq_transition_notifier_list+0x0/0x20 > initcall init_cpufreq_transition_notifier_list+0x0/0x20 returned 0 after 0 msecs > calling net_ns_init+0x0/0x190 > net_namespace: 676 bytes > initcall net_ns_init+0x0/0x190 returned 0 after 0 msecs > calling cpufreq_tsc+0x0/0x20 > initcall cpufreq_tsc+0x0/0x20 returned 0 after 0 msecs > calling reboot_init+0x0/0x20 > initcall reboot_init+0x0/0x20 returned 0 after 0 msecs > calling print_banner+0x0/0x10 > Booting paravirtualized kernel on bare hardware > > <----------------------- > > my guess is on: > > commit 1f7b94cd3d564901f9e04a8bc5832ae7bfd690a0 > Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > Date: Tue Aug 5 09:21:44 2008 -0700 > > rcu: classic RCU locking and memory-barrier cleanups > > Ingo Fixes a problem detected by lockdep in which rcu->lock was acquired both in irq context and in process context, but without disabling from process context. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: trace fix possible mem-leakSteven Rostedt2008-08-151-1/+6
| | | | | | | | | | | In the initialization of the RCU trace module, if rcupreempt_debugfs_init() fails, we never free the the trace buffer. This patch frees the trace buffer in case the debugfs fails. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: classic RCU locking and memory-barrier cleanupsPaul E. McKenney2008-08-151-10/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch simplifies the locking and memory-barrier usage in the Classic RCU grace-period-detection mechanism, incorporating Lai Jiangshan's feedback from the earlier version (http://lkml.org/lkml/2008/8/1/400 and http://lkml.org/lkml/2008/8/3/43). Passed 10 hours of rcutorture concurrent with CPUs being put online and taken offline on a 128-hardware-thread Power machine. My apologies to whoever in the Eastern Hemisphere was planning to use this machine over the Western Hemisphere night, but it was sitting idle and... So this is ready for tip/core/rcu. This patch is in preparation for moving to a hierarchical algorithm to allow the very large SMP machines -- requested by some people at OLS, and there seem to have been a few recent patches in the 4096-CPU direction as well. The general idea is to move to a much more conservative concurrency design, then apply a hierarchy to reduce contention on the global lock by a few orders of magnitude (larger machines would see greater reductions). The reason for taking a conservative approach is that this code isn't on any fast path. Prototype in progress. This patch is against the linux-tip git tree (tip/core/rcu). If you wish to test this against 2.6.26, use the following set of patches: http://www.rdrop.com/users/paulmck/patches/2.6.26-ljsimp-1.patch http://www.rdrop.com/users/paulmck/patches/2.6.26-ljsimpfix-3.patch The first patch combines commits 5127bed588a2f8f3a1f732de2a8a190b7df5dce3 and 3cac97cbb14aed00d83eb33d4613b0fe3aaea863 from Lai Jiangshan <laijs@cn.fujitsu.com>, and the second patch contains my changes. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: prevent console flood when one CPU sees another AWOL via RCUPaul E. McKenney2008-08-151-0/+1
| | | | | | | | | One small change needed to keep from flooding the console when one CPU notices that another is AWOL. Unless I am missing something subtle. Otherwise the cleanups look good! Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu, debug: detect stalled grace periods, cleanupsIngo Molnar2008-08-111-13/+13
| | | | | | small cleanups. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu, debug: detect stalled grace periodsPaul E. McKenney2008-08-111-0/+80
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this is a diagnostic patch for Classic RCU. The approach is to record a timestamp at the beginning of the grace period (in rcu_start_batch()), then have rcu_check_callbacks() complain if: 1. it is running on a CPU that has holding up grace periods for a long time (say one second). This will identify the culprit assuming that the culprit has not disabled hardware irqs, instruction execution, or some such. 2. it is running on a CPU that is not holding up grace periods, but grace periods have been held up for an even longer time (say two seconds). It is enabled via the default-off CONFIG_DEBUG_RCU_STALL kernel parameter. Rather than exponential backoff, it backs off to once per 30 seconds. My feeling upon thinking on it was that if you have stalled RCU grace periods for that long, a few extra printk() messages are probably the least of your worries... Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: David Witbrodt <dawitbro@sbcglobal.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'linus' into core/rcuIngo Molnar2008-08-1173-1897/+3112
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| * pm_qos: spelling fixesRichard Hughes2008-08-051-8/+8
| | | | | | | | | | | | | | | | | | | | A documentation cleanup patch. With a minor tweak to clarify units for kbs. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: mark gross <mgross@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * dma: fix order calculation in dma_mark_declared_memory_occupied()Jan Beulich2008-08-051-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_order() takes byte-sized input, not a page-granular one. Irrespective of this fix I'm inclined to believe that this doesn't work right anyway - bitmap_allocate_region() has an implicit assumption of 'pos' being suitable for 'order', which this function doesn't seem to enforce (and since it's being called with a byte-granular value there's no reason to believe that the callers would make sure device_addr is passed accordingly - it's also not documented that way). Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * genirq: better warning on irqchip->set_type() failureDavid Brownell2008-08-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | While I'm glad to finally see the hole fixed whereby passing an invalid IRQ trigger type to request_irq() would be ignored, the current diagnostic isn't quite useful. Fixed by also listing the trigger type which was rejected. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * semaphore: __down_common: use signal_pending_state()Oleg Nesterov2008-08-051-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change __down_common() to use signal_pending_state() instead of open coding. The changes in kernel/semaphore.o are just artifacts, the state checks are optimized away. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * relay: fix "full buffer with exactly full last subbuffer" accounting problemTom Zanussi2008-08-051-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In relay's current read implementation, if the buffer is completely full but hasn't triggered the buffer-full condition (i.e. the last write didn't cross the subbuffer boundary) and the last subbuffer is exactly full, the subbuffer accounting code erroneously finds nothing available. This patch fixes the problem. Signed-off-by: Tom Zanussi <tzanussi@gmail.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Andrea Righi <righi.andrea@gmail.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * Merge branch 'audit.b56' of ↵Linus Torvalds2008-08-041-0/+7
| |\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b56' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: Re: [PATCH] Fix the kernel panic of audit_filter_task when key field is set
| | * Re: [PATCH] Fix the kernel panic of audit_filter_task when key field is setzhangxiliang2008-08-041-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | Sorry, I miss a blank between if and "(". And I add "unlikely" to check "ctx" in audit_match_perm() and audit_match_filetype(). This is a new patch for it. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | __sched_setscheduler: don't do any policy checks when not "user"Jeremy Fitzhardinge2008-08-041-10/+12
| |/ | | | | | | | | | | | | | | | | | | | | | | | | The "user" parameter to __sched_setscheduler indicates whether the change is being done on behalf of a user process or not. If not, we shouldn't apply any permissions checks, so don't call security_task_setscheduler(). Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Tested-by: Steve Wise <swise@opengridcomputing.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * tracehook: fix exit_signal=0 caseRoland McGrath2008-08-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My commit 2b2a1ff64afbadac842bbc58c5166962cf4f7664 introduced a regression (sorry about that) for the odd case of exit_signal=0 (e.g. clone_flags=0). This is not a normal use, but it's used by a case in the glibc test suite. Dying with exit_signal=0 sends no signal, but it's supposed to wake up a parent's blocked wait*() calls (unlike the delayed_group_leader case). This fixes tracehook_notify_death() and its caller to distinguish a "signal 0" wakeup from the delayed_group_leader case (with no wakeup). Signed-off-by: Roland McGrath <roland@redhat.com> Tested-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2008-08-011-0/+1
| |\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: locking: fix mutex @key parameter kernel-doc notation
| | * locking: fix mutex @key parameter kernel-doc notationRandy Dunlap2008-07-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix @key parameter to mutex_init() and one of its callers. Warning(linux-2.6.26-git11//drivers/base/class.c:210): No description found for parameter 'key' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge branch 'for_linus' of ↵Linus Torvalds2008-08-011-25/+69
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kgdb: fix gdb serial thread queries kgdb: fix kgdb_validate_break_address to perform a mem write kgdb: remove the requirement for CONFIG_FRAME_POINTER
| | * | kgdb: fix gdb serial thread queriesJason Wessel2008-08-011-18/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The command "info threads" did not work correctly with kgdb. It would result in a silent kernel hang if used. This patach addresses several problems. - Fix use of deprecated NR_CPUS - Fix kgdb to not walk linearly through the pid space - Correctly implement shadow pids - Change the threads per query to a #define - Fix kgdb_hex2long to work with negated values The threads 0 and -1 are reserved to represent the current task. That means that CPU 0 will start with a shadow thread id of -2, and CPU 1 will have a shadow thread id of -3, etc... From the debugger you can switch to a shadow thread to see what one of the other cpus was doing, however it is not possible to execute run control operations on any other cpu execept the cpu executing the kgdb_handle_exception(). Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
| | * | kgdb: fix kgdb_validate_break_address to perform a mem writeJason Wessel2008-08-011-7/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A regression to the kgdb core was found in the case of using the CONFIG_DEBUG_RODATA kernel option. When this option is on, a breakpoint cannot be written into any readonly memory page. When an external debugger requests a breakpoint to get set, the kgdb_validate_break_address() was only checking to see if the address to place the breakpoint was readable and lacked a write check. This patch changes the validate routine to try reading (via the breakpoint set request) and also to try immediately writing the break point. If either fails, an error is correctly returned and the debugger behaves correctly. Then an end user can make the descision to use hardware breakpoints. Also update the documentation to reflect that using CONFIG_DEBUG_RODATA will inhibit the use of software breakpoints. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
| * | | [PATCH] Fix the bug of using AUDIT_STATUS_RATE_LIMIT when set fail, no error ↵zhangxiliang2008-08-011-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | output. When the "status_get->mask" is "AUDIT_STATUS_RATE_LIMIT || AUDIT_STATUS_BACKLOG_LIMIT". If "audit_set_rate_limit" fails and "audit_set_backlog_limit" succeeds, the "err" value will be greater than or equal to 0. It will miss the failure of rate set. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | [PATCH] Fix the kernel panic of audit_filter_task when key field is setzhangxiliang2008-08-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When calling audit_filter_task(), it calls audit_filter_rules() with audit_context is NULL. If the key field is set, the result in audit_filter_rules() will be set to 1 and ctx->filterkey will be set to key. But the ctx is NULL in this condition, so kernel will panic. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | Re: [PATCH] the loginuid field should be output in all AUDIT_CONFIG_CHANGE ↵zhangxiliang2008-08-011-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | audit messages > shouldn't these be using the "audit_get_loginuid(current)" and if we > are going to output loginuid we also should be outputting sessionid Thanks for your detailed explanation. I have made a new patch for outputing "loginuid" and "sessionid" by audit_get_loginuid(current) and audit_get_sessionid(current). If there are some deficiencies, please give me your indication. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | kernel/audit.c control character detection is off-by-oneVesa-Matti J Kari2008-08-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hello, According to my understanding there is an off-by-one bug in the function: audit_string_contains_control() in: kernel/audit.c Patch is included. I do not know from how many places the function is called from, but for example, SELinux Access Vector Cache tries to log untrusted filenames via call path: avc_audit() audit_log_untrustedstring() audit_log_n_untrustedstring() audit_string_contains_control() If audit_string_contains_control() detects control characters, then the string is hex-encoded. But the hex=0x7f dec=127, DEL-character, is not detected. I guess this could have at least some minor security implications, since a user can create a filename with 0x7f in it, causing logged filename to possibly look different when someone reads it on the terminal. Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | [PATCH] Audit: Collect signal info when SIGUSR2 is sent to auditdEric Paris2008-08-011-1/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Makes the kernel audit subsystem collect information about the sending process when that process sends SIGUSR2 to the userspace audit daemon. SIGUSR2 is a new interesting signal to auditd telling auditd that it should try to start logging to disk again and the error condition which caused it to stop logging to disk (usually out of space) has been rectified. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | sched: make scheduler sysfs attributes sysdev class devicesAndi Kleen2008-07-301-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | workqueues: add comments to __create_workqueue_key()Oleg Nesterov2008-07-301-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dmitry Adamushko pointed out that the error handling in __create_workqueue_key() is not clear, add the comment. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | printk: fix comment for printk ratelimitingUwe Kleine-König2008-07-301-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment assumed the burst to be one and the ratelimit used to be named printk_ratelimit_jiffies. Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | markers: fix markers read barrier for multiple probesMathieu Desnoyers2008-07-301-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Paul pointed out two incorrect read barriers in the marker handler code in the path where multiple probes are connected. Those are ordering reads of "ptype" (single or multi probe marker), "multi" array pointer, and "multi" array data access. It should be ordered like this : read ptype smp_rmb() read multi array pointer smp_read_barrier_depends() access data referenced by multi array pointer The code with a single probe connected (optimized case, does not have to allocate an array) has correct memory ordering. It applies to kernel 2.6.26.x, 2.6.25.x and linux-next. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | cpuset: clean up cpuset hierarchy traversal codeLi Zefan2008-07-301-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use cpuset.stack_list rather than kfifo, so we avoid memory allocation for kfifo. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | cpuset: fix wrong calculation of relax domain levelLi Zefan2008-07-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When multiple cpusets are overlapping in their 'cpus' and hence they form a single sched domain, the largest sched_relax_domain_level among those should be used. But when top_cpuset's sched_load_balance is set, its sched_relax_domain_level is used regardless other sub-cpusets'. This patch fixes it by walking the cpuset hierarchy to find the largest sched_relax_domain_level. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | cpuset: speed up sched domain partitionLai Jiangshan2008-07-301-4/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All child cpusets contain a subset of the parent's cpus, so we can skip them when partitioning sched domains. This decreases 'csa' greately for cpusets with multi-level hierarchy. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | cpuset: a bit cleanup for scan_for_empty_cpusets()Li Zefan2008-07-301-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clean up hierarchy traversal code Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Jackson <pj@sgi.com> Cc: Cliff Wickman <cpw@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | cgroup: uninline cgroup_has_css_refs()Li Zefan2008-07-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not small enough, and has 2 call sites. text data bss dec hex filename 12813 1676 4832 19321 4b79 cgroup.o.orig 12775 1676 4832 19283 4b53 cgroup.o Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.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>
| * | cgroup: remove duplicate code in allocate_cg_link()Li Zefan2008-07-301-18/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - just call free_cg_links() in allocate_cg_links() - the list will get initialized in allocate_cg_links(), so don't init it twice Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.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>
| * | cgroup: fix possible memory leakLi Zefan2008-07-301-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a leak if copy_from_user() returns failure. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.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>
| * | resource: add resource_size()Magnus Damm2008-07-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid one-off errors by introducing a resource_size() function. Signed-off-by: Magnus Damm <damm@igel.co.jp> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | Merge branch 'for-linus' of ↵Linus Torvalds2008-07-282-0/+155
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (21 commits) x86/PCI: use dev_printk when possible PCI: add D3 power state avoidance quirk PCI: fix bogus "'device' may be used uninitialized" warning in pci_slot PCI: add an option to allow ASPM enabled forcibly PCI: disable ASPM on pre-1.1 PCIe devices PCI: disable ASPM per ACPI FADT setting PCI MSI: Don't disable MSIs if the mask bit isn't supported PCI: handle 64-bit resources better on 32-bit machines PCI: rewrite PCI BAR reading code PCI: document pci_target_state PCI hotplug: fix typo in pcie hotplug output x86 gart: replace to_pages macro with iommu_num_pages x86, AMD IOMMU: replace to_pages macro with iommu_num_pages iommu: add iommu_num_pages helper function dma-coherent: add documentation to new interfaces Cris: convert to using generic dma-coherent mem allocator Sh: use generic per-device coherent dma allocator ARM: support generic per-device coherent dma mem Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVE x86: use generic per-device dma coherent allocator ...
| | * \ Merge branch 'linus' into core/generic-dma-coherentIngo Molnar2008-07-2965-1798/+2720
| | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/Kconfig Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | dma-coherent: add documentation to new interfacesDmitry Baryshkov2008-07-201-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVEDmitry Baryshkov2008-07-181-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't rewrite successfull allocation return values in case the memory was marked with DMA_MEMORY_EXCLUSIVE. Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | Merge branch 'linus' into core/generic-dma-coherentIngo Molnar2008-07-1869-1172/+11551
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | generic: per-device coherent dma allocatorDmitry Baryshkov2008-06-302-0/+128
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently x86_32, sh and cris-v32 provide per-device coherent dma memory allocator. However their implementation is nearly identical. Refactor out common code to be reused by them. Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | mmu-notifiers: coreAndrea Arcangeli2008-07-281-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With KVM/GFP/XPMEM there isn't just the primary CPU MMU pointing to pages. There are secondary MMUs (with secondary sptes and secondary tlbs) too. sptes in the kvm case are shadow pagetables, but when I say spte in mmu-notifier context, I mean "secondary pte". In GRU case there's no actual secondary pte and there's only a secondary tlb because the GRU secondary MMU has no knowledge about sptes and every secondary tlb miss event in the MMU always generates a page fault that has to be resolved by the CPU (this is not the case of KVM where the a secondary tlb miss will walk sptes in hardware and it will refill the secondary tlb transparently to software if the corresponding spte is present). The same way zap_page_range has to invalidate the pte before freeing the page, the spte (and secondary tlb) must also be invalidated before any page is freed and reused. Currently we take a page_count pin on every page mapped by sptes, but that means the pages can't be swapped whenever they're mapped by any spte because they're part of the guest working set. Furthermore a spte unmap event can immediately lead to a page to be freed when the pin is released (so requiring the same complex and relatively slow tlb_gather smp safe logic we have in zap_page_range and that can be avoided completely if the spte unmap event doesn't require an unpin of the page previously mapped in the secondary MMU). The mmu notifiers allow kvm/GRU/XPMEM to attach to the tsk->mm and know when the VM is swapping or freeing or doing anything on the primary MMU so that the secondary MMU code can drop sptes before the pages are freed, avoiding all page pinning and allowing 100% reliable swapping of guest physical address space. Furthermore it avoids the code that teardown the mappings of the secondary MMU, to implement a logic like tlb_gather in zap_page_range that would require many IPI to flush other cpu tlbs, for each fixed number of spte unmapped. To make an example: if what happens on the primary MMU is a protection downgrade (from writeable to wrprotect) the secondary MMU mappings will be invalidated, and the next secondary-mmu-page-fault will call get_user_pages and trigger a do_wp_page through get_user_pages if it called get_user_pages with write=1, and it'll re-establishing an updated spte or secondary-tlb-mapping on the copied page. Or it will setup a readonly spte or readonly tlb mapping if it's a guest-read, if it calls get_user_pages with write=0. This is just an example. This allows to map any page pointed by any pte (and in turn visible in the primary CPU MMU), into a secondary MMU (be it a pure tlb like GRU, or an full MMU with both sptes and secondary-tlb like the shadow-pagetable layer with kvm), or a remote DMA in software like XPMEM (hence needing of schedule in XPMEM code to send the invalidate to the remote node, while no need to schedule in kvm/gru as it's an immediate event like invalidating primary-mmu pte). At least for KVM without this patch it's impossible to swap guests reliably. And having this feature and removing the page pin allows several other optimizations that simplify life considerably. Dependencies: 1) mm_take_all_locks() to register the mmu notifier when the whole VM isn't doing anything with "mm". This allows mmu notifier users to keep track if the VM is in the middle of the invalidate_range_begin/end critical section with an atomic counter incraese in range_begin and decreased in range_end. No secondary MMU page fault is allowed to map any spte or secondary tlb reference, while the VM is in the middle of range_begin/end as any page returned by get_user_pages in that critical section could later immediately be freed without any further ->invalidate_page notification (invalidate_range_begin/end works on ranges and ->invalidate_page isn't called immediately before freeing the page). To stop all page freeing and pagetable overwrites the mmap_sem must be taken in write mode and all other anon_vma/i_mmap locks must be taken too. 2) It'd be a waste to add branches in the VM if nobody could possibly run KVM/GRU/XPMEM on the kernel, so mmu notifiers will only enabled if CONFIG_KVM=m/y. In the current kernel kvm won't yet take advantage of mmu notifiers, but this already allows to compile a KVM external module against a kernel with mmu notifiers enabled and from the next pull from kvm.git we'll start using them. And GRU/XPMEM will also be able to continue the development by enabling KVM=m in their config, until they submit all GRU/XPMEM GPLv2 code to the mainline kernel. Then they can also enable MMU_NOTIFIERS in the same way KVM does it (even if KVM=n). This guarantees nobody selects MMU_NOTIFIER=y if KVM and GRU and XPMEM are all =n. The mmu_notifier_register call can fail because mm_take_all_locks may be interrupted by a signal and return -EINTR. Because mmu_notifier_reigster is used when a driver startup, a failure can be gracefully handled. Here an example of the change applied to kvm to register the mmu notifiers. Usually when a driver startups other allocations are required anyway and -ENOMEM failure paths exists already. struct kvm *kvm_arch_create_vm(void) { struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL); + int err; if (!kvm) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); + kvm->arch.mmu_notifier.ops = &kvm_mmu_notifier_ops; + err = mmu_notifier_register(&kvm->arch.mmu_notifier, current->mm); + if (err) { + kfree(kvm); + return ERR_PTR(err); + } + return kvm; } mmu_notifier_unregister returns void and it's reliable. The patch also adds a few needed but missing includes that would prevent kernel to compile after these changes on non-x86 archs (x86 didn't need them by luck). [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix mm/filemap_xip.c build] [akpm@linux-foundation.org: fix mm/mmu_notifier.c build] Signed-off-by: Andrea Arcangeli <andrea@qumranet.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kanoj Sarcar <kanojsarcar@yahoo.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Chris Wright <chrisw@redhat.com> Cc: Marcelo Tosatti <marcelo@kvack.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Izik Eidus <izike@qumranet.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | Merge branch 'linus' into cpus4096Ingo Molnar2008-07-285-188/+158
| |\ \ \ \ \ | | | |_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: kernel/stop_machine.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds2008-07-285-189/+158
| | |\ \ \ \ | | | |_|_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: stop_machine: fix up ftrace.c stop_machine: Wean existing callers off stop_machine_run() stop_machine(): stop_machine_run() changed to use cpu mask Hotplug CPU: don't check cpu_online after take_cpu_down Simplify stop_machine stop_machine: add ALL_CPUS option module: fix build warning with !CONFIG_KALLSYMS
| | | * | | stop_machine: fix up ftrace.cRusty Russell2008-07-281-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simple conversion. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org>
| | | * | | stop_machine: Wean existing callers off stop_machine_run()Rusty Russell2008-07-282-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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