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* perf_counter, x86: Fix/improve apic fallbackIngo Molnar2009-08-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Johannes Stezenbach reported that his Pentium-M based laptop does not have the local APIC enabled by default, and hence perfcounters do not get initialized. Add a fallback for this case: allow non-sampled counters and return with an error on sampled counters. This allows 'perf stat' to work out of box - and allows 'perf top' and 'perf record' to fall back on a hrtimer based sampling method. ( Passing 'lapic' on the boot line will allow hardware sampling to occur - but if the APIC is disabled permanently by the hardware then this fallback still allows more systems to use perfcounters. ) Also decouple perfcounter support from X86_LOCAL_APIC. -v2: fix typo breaking counters on all other systems ... Reported-by: Johannes Stezenbach <js@sig21.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* intel-iommu: Restore DMAR_BROKEN_GFX_WA option for broken graphics driversDavid Woodhouse2009-07-041-0/+12
| | | | | | | | We need to give people a little more time to fix the broken drivers. Re-introduce this, but tied in properly with the 'iommu=pt' support this time. Change the config option name and make it default to 'no' too. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* intel-iommu: Clean up identity mapping code, remove CONFIG_DMAR_GFX_WADavid Woodhouse2009-06-291-13/+2
| | | | | | | | | | | | There's no need for the GFX workaround now we have 'iommu=pt' for the cases where people really care about performance. There's no need to have a special case for just one type of device. This also speeds up the iommu=pt path and reduces memory usage by setting up the si_domain _once_ and then using it for all devices, rather than giving each device its own private page tables. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-06-201-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits) tracing/urgent: warn in case of ftrace_start_up inbalance tracing/urgent: fix unbalanced ftrace_start_up function-graph: add stack frame test function-graph: disable when both x86_32 and optimize for size are configured ring-buffer: have benchmark test print to trace buffer ring-buffer: do not grab locks in nmi ring-buffer: add locks around rb_per_cpu_empty ring-buffer: check for less than two in size allocation ring-buffer: remove useless compile check for buffer_page size ring-buffer: remove useless warn on check ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index tracing: update sample event documentation tracing/filters: fix race between filter setting and module unload tracing/filters: free filter_string in destroy_preds() ring-buffer: use commit counters for commit pointer accounting ring-buffer: remove unused variable ring-buffer: have benchmark test handle discarded events ring-buffer: prevent adding write in discarded area tracing/filters: strloc should be unsigned short tracing/filters: operand can be negative ... Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
| * function-graph: add stack frame testSteven Rostedt2009-06-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case gcc does something funny with the stack frames, or the return from function code, we would like to detect that. An arch may implement passing of a variable that is unique to the function and can be saved on entering a function and can be tested when exiting the function. Usually the frame pointer can be used for this purpose. This patch also implements this for x86. Where it passes in the stack frame of the parent function, and will test that frame on exit. There was a case in x86_32 with optimize for size (-Os) where, for a few functions, gcc would align the stack frame and place a copy of the return address into it. The function graph tracer modified the copy and not the actual return address. On return from the funtion, it did not go to the tracer hook, but returned to the parent. This broke the function graph tracer, because the return of the parent (where gcc did not do this funky manipulation) returned to the location that the child function was suppose to. This caused strange kernel crashes. This test detected the problem and pointed out where the issue was. This modifies the parameters of one of the functions that the arch specific code calls, so it includes changes to arch code to accommodate the new prototype. Note, I notice that the parsic arch implements its own push_return_trace. This is now a generic function and the ftrace_push_return_trace should be used instead. This patch does not touch that code. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Helge Deller <deller@gmx.de> Cc: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | dma-mapping: x86: use asm-generic/dma-mapping-common.hFUJITA Tomonori2009-06-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Joerg Roedel <joerg.roedel@amd.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge commit 'linus/master' into HEADVegard Nossum2009-06-151-4/+41
|\ \ | |/ | | | | | | | | | | Conflicts: MAINTAINERS Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
| * Merge branch 'linus' into x86/mce3Ingo Molnar2009-06-111-17/+25
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/cpu/mcheck/mce_64.c arch/x86/kernel/irq.c Merge reason: Resolve the conflicts above. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * \ Merge branch 'irq/numa' into x86/mce3H. Peter Anvin2009-06-011-9/+3
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: arch/x86/kernel/irqinit_{32,64}.c unified in irq/numa and modified in x86/mce3; this merge resolves the conflict. Conflicts: arch/x86/kernel/irqinit.c Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | x86: trivial clean up for arch/x86/KconfigHidetoshi Seto2009-05-281-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use tab. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | x86, mce: add basic error injection infrastructureAndi Kleen2009-05-281-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow user programs to write mce records into /dev/mcelog. When they do that a fake machine check is triggered to test the machine check code. This uses the MCE MSR wrappers added earlier. The implementation is straight forward. There is a struct mce record per CPU and the MCE MSR accesses get data from there if there is valid data injected there. This allows to test the machine check code relatively realistically because only the lowest layer of hardware access is intercepted. The test suite and injector are available at git://git.kernel.org/pub/scm/utils/cpu/mce/mce-test.git git://git.kernel.org/pub/scm/utils/cpu/mce/mce-inject.git Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | x86, mce: enable MCE_AMD for 32bit NEW_MCEAndi Kleen2009-05-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | That's very easy using the infrastructure enabled earlier for MCE_INTEL Untested. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | x86, mce: enable MCE_INTEL for 32bit new MCEAndi Kleen2009-05-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enable the 64bit MCE_INTEL code (CMCI, thermal interrupts) for 32bit NEW_MCE. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | x86, mce: use 64bit machine check code on 32bitAndi Kleen2009-05-281-2/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 64bit machine check code is in many ways much better than the 32bit machine check code: it is more specification compliant, is cleaner, only has a single code base versus one per CPU, has better infrastructure for recovery, has a cleaner way to communicate with user space etc. etc. Use the 64bit code for 32bit too. This is the second attempt to do this. There was one a couple of years ago to unify this code for 32bit and 64bit. Back then this ran into some trouble with K7s and was reverted. I believe this time the K7 problems (and some others) are addressed. I went over the old handlers and was very careful to retain all quirks. But of course this needs a lot of testing on old systems. On newer 64bit capable systems I don't expect much problems because they have been already tested with the 64bit kernel. I made this a CONFIG for now that still allows to select the old machine check code. This is mostly to make testing easier, if someone runs into a problem we can ask them to try with the CONFIG switched. The new code is default y for more coverage. Once there is confidence the 64bit code works well on older hardware too the CONFIG_X86_OLD_MCE and the associated code can be easily removed. This causes a behaviour change for 32bit installations. They now have to install the mcelog package to be able to log corrected machine checks. The 64bit machine check code only handles CPUs which support the standard Intel machine check architecture described in the IA32 SDM. The 32bit code has special support for some older CPUs which have non standard machine check architectures, in particular WinChip C3 and Intel P5. I made those a separate CONFIG option and kept them for now. The WinChip variant could be probably removed without too much pain, it doesn't really do anything interesting. P5 is also disabled by default (like it was before) because many motherboards have it miswired, but according to Alan Cox a few embedded setups use that one. Forward ported/heavily changed version of old patch, original patch included review/fixes from Thomas Gleixner, Bert Wesarg. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | | | kmemcheck: make kconfig accessible for other architecturesPekka Enberg2009-06-151-0/+1
| |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Kconfig options of kmemcheck are hidden under arch/x86 which makes porting to other architectures harder. To fix that, move the Kconfig bits to lib/Kconfig.kmemcheck and introduce a CONFIG_HAVE_ARCH_KMEMCHECK config option that architectures can define. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> [rebased for mainline inclusion] Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
* | | Merge branch 'linus' into perfcounters/coreIngo Molnar2009-06-111-26/+27
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/irqinit.c arch/x86/kernel/irqinit_64.c arch/x86/kernel/traps.c arch/x86/mm/fault.c include/linux/sched.h kernel/exit.c
| * \ \ Merge branch 'x86-kbuild-for-linus' of ↵Linus Torvalds2009-06-101-17/+24
| |\ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-kbuild-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (46 commits) x86, boot: add new generated files to the appropriate .gitignore files x86, boot: correct the calculation of ZO_INIT_SIZE x86-64: align __PHYSICAL_START, remove __KERNEL_ALIGN x86, boot: correct sanity checks in boot/compressed/misc.c x86: add extension fields for bootloader type and version x86, defconfig: update kernel position parameters x86, defconfig: update to current, no material changes x86: make CONFIG_RELOCATABLE the default x86: default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN to 16 MB x86: document new bzImage fields x86, boot: make kernel_alignment adjustable; new bzImage fields x86, boot: remove dead code from boot/compressed/head_*.S x86, boot: use LOAD_PHYSICAL_ADDR on 64 bits x86, boot: make symbols from the main vmlinux available x86, boot: determine compressed code offset at compile time x86, boot: use appropriate rep string for move and clear x86, boot: zero EFLAGS on 32 bits x86, boot: set up the decompression stack as early as possible x86, boot: straighten out ranges to copy/zero in compressed/head*.S x86, boot: stylistic cleanups for boot/compressed/head_64.S ... Fixed trivial conflict in arch/x86/configs/x86_64_defconfig manually
| | * | x86: make CONFIG_RELOCATABLE the defaultH. Peter Anvin2009-05-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the EXPERIMENTAL tag from CONFIG_RELOCATABLE and make it the default. Relocatable kernels have been used for a while now, and should now have identical semantics to non-relocatable kernels when loaded by a non-relocating bootloader. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | * | x86: default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN to 16 MBH. Peter Anvin2009-05-111-15/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN each to 16 MB, so that both non-relocatable and relocatable kernels are loaded at 16 MB by a non-relocating bootloader. This is somewhat hacky, but it appears to be the only way to do this that does not break some some set of existing bootloaders. We want to avoid the bottom 16 MB because of large page breakup, memory holes, and ZONE_DMA. Embedded systems may need to reduce this, or update their bootloaders to be aware of the new min_alignment field. [ Impact: performance improvement, avoids problems on some systems ] Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | * | x86: add a Kconfig symbol for when relocations are neededH. Peter Anvin2009-05-081-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We only need to build relocations when we are building a 32-bit relocatable kernel. Rather than unnecessarily complicating the Makefiles, make an explicit Kbuild symbol for this. [ Impact: permits future cleanup ] Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Sam Ravnborg <sam@ravnborg.org>
| | * | x86: unify arch/x86/boot/compressed/vmlinux_*.ldsLinus Torvalds2009-04-271-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Look at the: diff -u arch/x86/boot/compressed/vmlinux_*.lds output and realize that they're basially exactly the same except for trivial naming differences, and the fact that the 64-bit version has a "pgtable" thing. So unify them. There's some trivial cleanup there (make the output format a Kconfig thing rather than doing #ifdef's for it, and unify both 32-bit and 64-bit BSS end to "_ebss", where 32-bit used to use the traditional "_end"), but other than that it's really very mindless and straigt conversion. For example, I think we should aim to remove "startup_32" vs "startup_64", and just call it "startup", and get rid of one more difference. I didn't do that. Also, notice the comment in the unified vmlinux.lds.S talks about "head_64" and "startup_32" which is an odd and incorrect mix, but that was actually what the old 64-bit only lds file had, so the confusion isn't new, and now that mixing is arguably more accurate thanks to the vmlinux.lds.S file being shared between the two cases ;) [ Impact: cleanup, unification ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge branch 'linus' into irq/numaIngo Molnar2009-06-011-0/+13
| |\ \ \ | | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/mips/sibyte/bcm1480/irq.c arch/mips/sibyte/sb1250/irq.c Merge reason: we gathered a few conflicts plus update to latest upstream fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge branch 'x86/apic' into irq/numaIngo Molnar2009-05-011-1/+1
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/apic/io_apic.c Merge reason: non-trivial interaction between ongoing work in io_apic.c and the NUMA migration feature in the irq tree. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | x86: x2apic, IR: Make config X86_UV dependent on X86_X2APICSuresh Siddha2009-04-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of selecting X86_X2APIC, make config X86_UV dependent on X86_X2APIC. This will eliminate enabling CONFIG_X86_X2APIC with out enabling CONFIG_INTR_REMAP. [ Impact: cleanup ] Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Jack Steiner <steiner@sgi.com> Cc: dwmw2@infradead.org Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Weidong Han <weidong.han@intel.com> LKML-Reference: <20090420200450.694598000@linux-os.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86/irq: use move_irq_desc() in create_irq_nr()Yinghai Lu2009-05-011-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | move_irq_desc() will try to move irq_desc to the home node if the allocated one is not correct, in create_irq_nr(). ( This can happen on devices that are on different nodes that are using MSI, when drivers are loaded and unloaded randomly. ) v2: fix non-smp build v3: add NUMA_IRQ_DESC to eliminate #ifdefs [ Impact: improve irq descriptor locality on NUMA systems ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <49F95EAE.2050903@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86/irq: remove leftover code from NUMA_MIGRATE_IRQ_DESCYinghai Lu2009-04-281-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original feature of migrating irq_desc dynamic was too fragile and was causing problems: it caused crashes on systems with lots of cards with MSI-X when user-space irq-balancer was enabled. We now have new patches that create irq_desc according to device numa node. This patch removes the leftover bits of the dynamic balancer. [ Impact: remove dead code ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <49F654AF.8000808@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | Merge branch 'linus' into perfcounters/coreIngo Molnar2009-06-011-0/+13
|\ \ \ \ \ | | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | Merge reason: merge almost-rc8 into perfcounters/core, which was -rc6 based - to pick up the latest upstream fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | x86: Fix performance regression caused by paravirt_ops on native kernelsJeremy Fitzhardinge2009-05-151-0/+13
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Xiaohui Xin and some other folks at Intel have been looking into what's behind the performance hit of paravirt_ops when running native. It appears that the hit is entirely due to the paravirtualized spinlocks introduced by: | commit 8efcbab674de2bee45a2e4cdf97de16b8e609ac8 | Date: Mon Jul 7 12:07:51 2008 -0700 | | paravirt: introduce a "lock-byte" spinlock implementation The extra call/return in the spinlock path is somehow causing an increase in the cycles/instruction of somewhere around 2-7% (seems to vary quite a lot from test to test). The working theory is that the CPU's pipeline is getting upset about the call->call->locked-op->return->return, and seems to be failing to speculate (though I haven't seen anything definitive about the precise reasons). This doesn't entirely make sense, because the performance hit is also visible on unlock and other operations which don't involve locked instructions. But spinlock operations clearly swamp all the other pvops operations, even though I can't imagine that they're nearly as common (there's only a .05% increase in instructions executed). If I disable just the pv-spinlock calls, my tests show that pvops is identical to non-pvops performance on native (my measurements show that it is actually about .1% faster, but Xiaohui shows a .05% slowdown). Summary of results, averaging 10 runs of the "mmperf" test, using a no-pvops build as baseline: nopv Pv-nospin Pv-spin CPU cycles 100.00% 99.89% 102.18% instructions 100.00% 100.10% 100.15% CPI 100.00% 99.79% 102.03% cache ref 100.00% 100.84% 100.28% cache miss 100.00% 90.47% 88.56% cache miss rate 100.00% 89.72% 88.31% branches 100.00% 99.93% 100.04% branch miss 100.00% 103.66% 107.72% branch miss rt 100.00% 103.73% 107.67% wallclock 100.00% 99.90% 102.20% The clear effect here is that the 2% increase in CPI is directly reflected in the final wallclock time. (The other interesting effect is that the more ops are out of line calls via pvops, the lower the cache access and miss rates. Not too surprising, but it suggests that the non-pvops kernel is over-inlined. On the flipside, the branch misses go up correspondingly...) So, what's the fix? Paravirt patching turns all the pvops calls into direct calls, so _spin_lock etc do end up having direct calls. For example, the compiler generated code for paravirtualized _spin_lock is: <_spin_lock+0>: mov %gs:0xb4c8,%rax <_spin_lock+9>: incl 0xffffffffffffe044(%rax) <_spin_lock+15>: callq *0xffffffff805a5b30 <_spin_lock+22>: retq The indirect call will get patched to: <_spin_lock+0>: mov %gs:0xb4c8,%rax <_spin_lock+9>: incl 0xffffffffffffe044(%rax) <_spin_lock+15>: callq <__ticket_spin_lock> <_spin_lock+20>: nop; nop /* or whatever 2-byte nop */ <_spin_lock+22>: retq One possibility is to inline _spin_lock, etc, when building an optimised kernel (ie, when there's no spinlock/preempt instrumentation/debugging enabled). That will remove the outer call/return pair, returning the instruction stream to a single call/return, which will presumably execute the same as the non-pvops case. The downsides arel 1) it will replicate the preempt_disable/enable code at eack lock/unlock callsite; this code is fairly small, but not nothing; and 2) the spinlock definitions are already a very heavily tangled mass of #ifdefs and other preprocessor magic, and making any changes will be non-trivial. The other obvious answer is to disable pv-spinlocks. Making them a separate config option is fairly easy, and it would be trivial to enable them only when Xen is enabled (as the only non-default user). But it doesn't really address the common case of a distro build which is going to have Xen support enabled, and leaves the open question of whether the native performance cost of pv-spinlocks is worth the performance improvement on a loaded Xen system (10% saving of overall system CPU when guests block rather than spin). Still it is a reasonable short-term workaround. [ Impact: fix pvops performance regression when running native ] Analysed-by: "Xin Xiaohui" <xiaohui.xin@intel.com> Analysed-by: "Li Xin" <xin.li@intel.com> Analysed-by: "Nakajima Jun" <jun.nakajima@intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Xen-devel <xen-devel@lists.xensource.com> LKML-Reference: <4A0B62F7.5030802@goop.org> [ fixed the help text ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'linus' into perfcounters/coreIngo Molnar2009-04-291-5/+4
|\ \ \ \ | |/ / / | | | | | | | | | | | | | | | | | | | | Merge reason: This brach was on -rc1, refresh it to almost-rc4 to pick up the latest upstream fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-04-261-0/+1
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, hpet: Stop soliciting hpet=force users on ICH4M x86: check boundary in setup_node_bootmem() uv_time: add parameter to uv_read_rtc() x86: hpet: fix periodic mode programming on AMD 81xx x86: more than 8 32-bit CPUs requires X86_BIGSMP x86: avoid theoretical spurious NMI backtraces with CONFIG_CPUMASK_OFFSTACK=y x86: fix boot crash in NMI watchdog with CONFIG_CPUMASK_OFFSTACK=y and flat APIC x86-64: fix FPU corruption with signals and preemption x86/uv: fix for no memory at paddr 0 docs, x86: add nox2apic back to kernel-parameters.txt x86: mm/numa_32.c calculate_numa_remap_pages should use __init x86, kbuild: make "make install" not depend on vmlinux x86/uv: fix init of cpu-less nodes x86/uv: fix init of memory-less nodes
| | * | | x86: more than 8 32-bit CPUs requires X86_BIGSMPMichael K. Johnson2009-04-211-0/+1
| | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | $ cat x86-more-than-8-cpus-requires-bigsmp.patch Enforce NR_CPUS <= 8 limitation if X86_BIGSMP not set Configuring more than 8 logical CPUs on 32-bit x86 requires X86_BIGSMP to be set in order to boot successfully, if more than 8 logical CPUs are actually found at boot time. The X86_BIGSMP help text describes that it is required to be set if more than 8 CPUs are configured, but this was previously not enforced. This configuration error has affected multiple distributions: https://bugzilla.redhat.com/show_bug.cgi?id=480844 https://issues.rpath.com/browse/RPL-3022 Signed-off-by: Michael K Johnson <johnsonm@rpath.com> LKML-Reference: <20090422014448.GB32541@logo.rdu.rpath.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds2009-04-261-0/+1
| |\ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86/irq: mark NUMA_MIGRATE_IRQ_DESC broken x86, irq: Remove IRQ_DISABLED check in process context IRQ move
| | * | x86/irq: mark NUMA_MIGRATE_IRQ_DESC brokenYinghai Lu2009-04-171-0/+1
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It causes crash on system with lots of cards with MSI-X when irq_balancer enabled... The patches fixing it were both complex and fragile, according to Eric they were also doing quite dangerous things to the hardware. Instead we now have patches that solve this problem via static NUMA node mappings - not dynamic allocation and balancing. The patches are much simpler than this method but are still too large outside of the merge window, so we mark the dynamic balancer as broken for now, and queue up the new approach for v2.6.31. [ Impact: deactivate broken kernel feature ] Reported-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <49E68C41.4020801@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge branch 'x86/uv' of ↵Linus Torvalds2009-04-161-0/+1
| |\ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86/uv' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: UV BAU distribution and payload MMRs x86: UV: BAU partition-relative distribution map x86, uv: add Kconfig dependency on NUMA for UV systems x86: prevent /sys/firmware/sgi_uv from being created on non-uv systems x86, UV: Fix for nodes with memory and no cpus x86, UV: system table in bios accessed after unmap x86: UV BAU messaging timeouts x86: UV BAU and nodes with no memory
| | * x86, uv: add Kconfig dependency on NUMA for UV systemsJack Steiner2009-04-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: build fix Add Kconfig dependency on NUMA for enabling UV. Although it might be possible to configure non-NUMA UV systems, they are unsupported and not interesting. Much of the infrastructure for UV requires NUMA support. Signed-off-by: Jack Steiner <steiner@sgi.com> LKML-Reference: <20090403203942.GA20137@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | x86, intel-iommu: fix X2APIC && !ACPI build failureDavid Woodhouse2009-04-071-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This build failure: | drivers/pci/dmar.c:47: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘dmar_tbl_size’ | drivers/pci/dmar.c:62: warning: ‘struct acpi_dmar_device_scope’ declared inside parameter list | drivers/pci/dmar.c:62: warning: its scope is only this definition or declaration, which is probably not what you want Triggers due to this commit: d0b03bd: x2apic/intr-remap: decouple interrupt remapping from x2apic Which exposed a pre-existing but dormant fragility of the 'select X86_X2APIC' it moved around and turned that fragility into a build failure. Replace it with a proper 'depends on' construct. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> LKML-Reference: <1239084280.22733.404.camel@macbook.infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'linus' into perfcounters/coreIngo Molnar2009-04-071-1/+1
|\ \ \ | |/ / | | | | | | | | | | | | | | | | | | Merge reason: need the upstream facility added by: 7f1e2ca: hrtimer: fix rq->lock inversion (again) Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge git://git.infradead.org/iommu-2.6Linus Torvalds2009-04-061-1/+1
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.infradead.org/iommu-2.6: drivers/pci/intr_remapping.c: include acpi.h intel-iommu: Fix oops in device_to_iommu() when devices not found. intel-iommu: Handle PCI domains appropriately. intel-iommu: Fix device-to-iommu mapping for PCI-PCI bridges. x2apic/intr-remap: decouple interrupt remapping from x2apic x86, dmar: check if it's initialized before disable queue invalidation intel-iommu: set compatibility format interrupt Intel IOMMU Suspend/Resume Support - Interrupt Remapping Intel IOMMU Suspend/Resume Support - Queued Invalidation Intel IOMMU Suspend/Resume Support - DMAR intel-iommu: Add for_each_iommu() and for_each_active_iommu() macros
| | * | x2apic/intr-remap: decouple interrupt remapping from x2apicHan, Weidong2009-04-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | interrupt remapping must be enabled before enabling x2apic, but interrupt remapping doesn't depend on x2apic, it can be used separately. Enable interrupt remapping in init_dmars even x2apic is not supported. [dwmw2: Update Kconfig accordingly, fix build with INTR_REMAP && !X2APIC] Signed-off-by: Weidong Han <weidong.han@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | | | Merge branch 'linus' into perfcounters/core-v2Ingo Molnar2009-04-061-7/+33
|\ \ \ \ | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: we have gathered quite a few conflicts, need to merge upstream Conflicts: arch/powerpc/kernel/Makefile arch/x86/ia32/ia32entry.S arch/x86/include/asm/hardirq.h arch/x86/include/asm/unistd_32.h arch/x86/include/asm/unistd_64.h arch/x86/kernel/cpu/common.c arch/x86/kernel/irq.c arch/x86/kernel/syscall_table_32.S arch/x86/mm/iomap_32.c include/linux/sched.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge branch 'tracing-for-linus' of ↵Linus Torvalds2009-04-051-0/+2
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits) tracing, net: fix net tree and tracing tree merge interaction tracing, powerpc: fix powerpc tree and tracing tree interaction ring-buffer: do not remove reader page from list on ring buffer free function-graph: allow unregistering twice trace: make argument 'mem' of trace_seq_putmem() const tracing: add missing 'extern' keywords to trace_output.h tracing: provide trace_seq_reserve() blktrace: print out BLK_TN_MESSAGE properly blktrace: extract duplidate code blktrace: fix memory leak when freeing struct blk_io_trace blktrace: fix blk_probes_ref chaos blktrace: make classic output more classic blktrace: fix off-by-one bug blktrace: fix the original blktrace blktrace: fix a race when creating blk_tree_root in debugfs blktrace: fix timestamp in binary output tracing, Text Edit Lock: cleanup tracing: filter fix for TRACE_EVENT_FORMAT events ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release() x86: kretprobe-booster interrupt emulation code fix ... Fix up trivial conflicts in arch/parisc/include/asm/ftrace.h include/linux/memory.h kernel/extable.c kernel/module.c
| | * \ \ Merge branch 'tracing/core-v2' into tracing-for-linusIngo Molnar2009-04-021-0/+2
| | |\ \ \ | | | |_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: include/linux/slub_def.h lib/Kconfig.debug mm/slob.c mm/slub.c
| | | * | Merge branch 'x86/asm' into tracing/syscallsIngo Molnar2009-03-141-1/+7
| | | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need the wider TIF work-mask checks in entry_32.S. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | tracing/x86: basic implementation of syscall tracing for x86Frederic Weisbecker2009-03-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide the x86 trace callbacks to trace syscalls. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <1236401580-5758-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | Merge branch 'x86/core' into tracing/texteditIngo Molnar2009-03-061-317/+345
| | | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/Kconfig block/blktrace.c kernel/irq/handle.c Semantic conflict: kernel/trace/blktrace.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * \ \ \ Merge branches 'tracing/ftrace', 'tracing/mmiotrace' and 'linus' into ↵Ingo Molnar2009-03-021-1/+1
| | | |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | tracing/core
| | | * \ \ \ \ Merge branches 'tracing/ftrace', 'tracing/ring-buffer', 'tracing/sysprof', ↵Ingo Molnar2009-02-131-0/+11
| | | |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | 'tracing/urgent' and 'linus' into tracing/core
| | | * | | | | | ftrace: change function graph tracer to use new in_nmiSteven Rostedt2009-02-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function graph tracer piggy backed onto the dynamic ftracer to use the in_nmi custom code for dynamic tracing. The problem was (as Andrew Morton pointed out) it really only wanted to bail out if the context of the current CPU was in NMI context. But the dynamic ftrace in_nmi custom code was true if _any_ CPU happened to be in NMI context. Now that we have a generic in_nmi interface, this patch changes the function graph code to use it instead of the dynamic ftarce custom code. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| | | * | | | | | ring-buffer: add NMI protection for spinlocksSteven Rostedt2009-02-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: prevent deadlock in NMI The ring buffers are not yet totally lockless with writing to the buffer. When a writer crosses a page, it grabs a per cpu spinlock to protect against a reader. The spinlocks taken by a writer are not to protect against other writers, since a writer can only write to its own per cpu buffer. The spinlocks protect against readers that can touch any cpu buffer. The writers are made to be reentrant with the spinlocks disabling interrupts. The problem arises when an NMI writes to the buffer, and that write crosses a page boundary. If it grabs a spinlock, it can be racing with another writer (since disabling interrupts does not protect against NMIs) or with a reader on the same CPU. Luckily, most of the users are not reentrant and protects against this issue. But if a user of the ring buffer becomes reentrant (which is what the ring buffers do allow), if the NMI also writes to the ring buffer then we risk the chance of a deadlock. This patch moves the ftrace_nmi_enter called by nmi_enter() to the ring buffer code. It replaces the current ftrace_nmi_enter that is used by arch specific code to arch_ftrace_nmi_enter and updates the Kconfig to handle it. When an NMI is called, it will set a per cpu variable in the ring buffer code and will clear it when the NMI exits. If a write to the ring buffer crosses page boundaries inside an NMI, a trylock is used on the spin lock instead. If the spinlock fails to be acquired, then the entry is discarded. This bug appeared in the ftrace work in the RT tree, where event tracing is reentrant. This workaround solved the deadlocks that appeared there. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| * | | | | | | | Merge branch 'for-linus' of ↵Linus Torvalds2009-04-031-2/+2
| |\ \ \ \ \ \ \ \ | | |_|_|_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits) trivial: Update my email address trivial: NULL noise: drivers/mtd/tests/mtd_*test.c trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h trivial: Fix misspelling of "Celsius". trivial: remove unused variable 'path' in alloc_file() trivial: fix a pdlfush -> pdflush typo in comment trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL trivial: wusb: Storage class should be before const qualifier trivial: drivers/char/bsr.c: Storage class should be before const qualifier trivial: h8300: Storage class should be before const qualifier trivial: fix where cgroup documentation is not correctly referred to trivial: Give the right path in Documentation example trivial: MTD: remove EOL from MODULE_DESCRIPTION trivial: Fix typo in bio_split()'s documentation trivial: PWM: fix of #endif comment trivial: fix typos/grammar errors in Kconfig texts trivial: Fix misspelling of firmware trivial: cgroups: documentation typo and spelling corrections trivial: Update contact info for Jochen Hein trivial: fix typo "resgister" -> "register" ...
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