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* Merge branch 'perfcounters/urgent' into perfcounters/coreIngo Molnar2009-08-245-2/+38
|\ | | | | | | | | | | | | | | | | | | Conflicts: tools/perf/builtin-annotate.c tools/perf/builtin-report.c Merge reason: resolve these conflicts. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter: Fix typo in read() output generationPeter Zijlstra2009-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When you iterate a list, using the iterator is useful. Before: ID: 5 ID: 5 ID: 5 ID: 5 EVNT: 0x40088b scale: nan ID: 5 CNT: 1006252 ID: 6 CNT: 1011090 ID: 7 CNT: 1011196 ID: 8 CNT: 1011095 EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 2003065 ID: 6 CNT: 2011671 ID: 7 CNT: 2012620 ID: 8 CNT: 2013479 EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 3002390 ID: 6 CNT: 3015996 ID: 7 CNT: 3018019 ID: 8 CNT: 3020006 EVNT: 0x40088b scale: 1.000000 ID: 5 CNT: 4002406 ID: 6 CNT: 4021120 ID: 7 CNT: 4024241 ID: 8 CNT: 4027059 After: ID: 1 ID: 2 ID: 3 ID: 4 EVNT: 0x400889 scale: nan ID: 1 CNT: 1005270 ID: 2 CNT: 1009833 ID: 3 CNT: 1010065 ID: 4 CNT: 1010088 EVNT: 0x400898 scale: nan ID: 1 CNT: 2001531 ID: 2 CNT: 2022309 ID: 3 CNT: 2022470 ID: 4 CNT: 2022627 EVNT: 0x400888 scale: 0.489467 ID: 1 CNT: 3001261 ID: 2 CNT: 3027088 ID: 3 CNT: 3027941 ID: 4 CNT: 3028762 Reported-by: stephane eranian <eranian@googlemail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey J Ashford <cjashfor@us.ibm.com> Cc: perfmon2-devel <perfmon2-devel@lists.sourceforge.net> LKML-Reference: <1250867976.7538.73.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: Check perf.data ownerPeter Zijlstra2009-08-192-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an owner check to opening perf.data files and a switch to silence it. Because perf-report/perf-annotate are binary parsers reading another users' perf.data file could be a security risk if the file were explicitly engineered to trigger bugs in the parser (we hope of course there are non such bugs, but you never know). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20090819092023.896648538@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: Make 'make html' workKyle McMartin2009-08-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pushd tools/perf/Documentation make html popd is failing for me... ASCIIDOC perf-annotate.html ERROR: unsafe: include file: /etc/asciidoc/./stylesheets/xhtml11.css ERROR: unsafe: include file: /etc/asciidoc/./stylesheets/xhtml11-manpage.css ERROR: unsafe: include file: /etc/asciidoc/./stylesheets/xhtml11-quirks.css make: *** [perf-annotate.html] Error 1 Apparently asciidoc "unsafe" is the default mode of operation in practice. https://bugzilla.redhat.com/show_bug.cgi?id=506953 Works tidily now. Signed-off-by: Kyle McMartin <kyle@redhat.com> 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: <20090818164125.GM25206@bombadil.infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf annotate: Fix segmentation faultIngo Molnar2009-08-181-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus reported this perf annotate segfault: [torvalds@nehalem git]$ perf annotate unmap_vmas Segmentation fault #0 map__clone (self=<value optimized out>) at builtin-annotate.c:236 #1 thread__fork (self=<value optimized out>) at builtin-annotate.c:372 The bug here was that builtin-annotate.c was a copy of builtin-report.c and a threading related fix to builtin-report.c didnt get propagated to builtin-annotate.c ... Reported-by: Linus Torvalds <torvalds@linux-foundation.org> 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>
| * perf_counter: Fix the PARISC buildIngo Molnar2009-08-181-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PARISC does not build: /home/mingo/tip/kernel/perf_counter.c: In function 'perf_counter_index': /home/mingo/tip/kernel/perf_counter.c:2016: error: 'PERF_COUNTER_INDEX_OFFSET' undeclared (first use in this function) /home/mingo/tip/kernel/perf_counter.c:2016: error: (Each undeclared identifier is reported only once /home/mingo/tip/kernel/perf_counter.c:2016: error: for each function it appears in.) As PERF_COUNTER_INDEX_OFFSET is not defined. Now, we could define it in the architecture - but lets also provide a core default of 0 (which happens to be what all but one architecture uses at the moment). Architectures that need a different index offset should set this value in their asm/perf_counter.h files. Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org 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>
| * perf_counter: Check task on counter read IPIPaul Mackerras2009-08-171-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In general, code in perf_counter.c that is called through an IPI checks, for per-task counters, that the counter's task is still the current task. This is to handle the race condition where the cpu switches from the task we want to another task in the interval between sending the IPI and the IPI arriving and being handled on the target CPU. For some reason, __perf_counter_read is missing this check, yet there is no reason why the race condition can't occur. This adds a check that the current task is the one we want. If it isn't, we just return. In that case the counter->count value should be up to date, since it will have been updated when the counter was scheduled out, which must have happened since the IPI was sent. I don't have an example of an actual failure due to this race, but it seems obvious that it could occur and we need to guard against it. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <19076.63614.277861.368125@drongo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf: Rename perf-examples.txt to examples.txtCarlos R. Mafra2009-08-171-0/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename it to examples.txt to avoid the perf-*.txt pattern in the Makefile, otherwise 'make doc' fails because perf-examples.txt is not formatted to be a man page: ERROR: perf-examples.txt: line 1: manpage document title is mandatory Signed-off-by: Carlos R. Mafra <crmafra@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | perf tools: Save partial non-overlapping mapFrederic Weisbecker2009-08-181-3/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The librarization of the thread helpers between annotate and report lost some perf report specifics. thread__insert_map() had its most uptodate version in perf report which cared about partial map overlapping. In case of overlap between two maps, perf annotate's version removes the whole old map without considering if it partially or absolutely overlaps the new map. We exported the odd version, change it by using the perf report version. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250607843-7395-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | perf tools: Fix comm column adjustingFrederic Weisbecker2009-08-181-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The librarization of the thread helpers between annotate and report lost some perf report specifics. This patch fixes the thread comm column adjusting that has been omitted during this export. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250604226-6852-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | perf tools: Remove obsolete definesIngo Molnar2009-08-181-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The _XOPEN_SOURCE* defines are not really needed on Linux and it's not like we'll port this to AIX ;-) The define also broke the build with gcc 4.4.1: CC util/trace-event-parse.o In file included from util/trace-event-parse.c:32: util/util.h:43:1: error: "_XOPEN_SOURCE" redefined So remove them. 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>
* | Merge branch 'master' of ↵Ingo Molnar2009-08-187-16/+588
|\ \ | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulus/perfcounters into perfcounters/core
| * | perf_counter: powerpc: Add callchain supportPaul Mackerras2009-08-182-1/+528
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for tracing callchains for powerpc, both 32-bit and 64-bit, and both in the kernel and userspace, from PMU interrupt context. The first three entries stored for each callchain are the NIP (next instruction pointer), LR (link register), and the contents of the LR save area in the second stack frame (the first is ignored because the ABI convention on powerpc is that functions save their return address in their caller's stack frame). Because leaf functions don't have to save their return address (LR value) and don't have to establish a stack frame, it's possible for either or both of LR and the second stack frame's LR save area to have valid return addresses in them. This is basically impossible to disambiguate without either reading the code or looking at auxiliary information such as CFI tables. Since we don't want to do either of those things at interrupt time, we store both LR and the second stack frame's LR save area. Once we get past the second stack frame, there is no ambiguity; all return addresses we get are reliable. For kernel traces, we check whether they are valid kernel instruction addresses and store zero instead if they are not (rather than omitting them, which would make it impossible for userspace to know which was which). We also store zero instead of the second stack frame's LR save area value if it is the same as LR. For kernel traces, we check for interrupt frames, and for user traces, we check for signal frames. In each case, since we're starting a new trace, we store a PERF_CONTEXT_KERNEL/USER marker so that userspace knows that the next three entries are NIP, LR and the second stack frame for the interrupted context. We read user memory with __get_user_inatomic. On 64-bit, if this PMU interrupt occurred while interrupts are soft-disabled, and there is no MMU hash table entry for the page, we will get an -EFAULT return from __get_user_inatomic even if there is a valid Linux PTE for the page, since hash_page isn't reentrant. Thus we have code here to read the Linux PTE and access the page via the kernel linear mapping. Since 64-bit doesn't use (or need) highmem there is no need to do kmap_atomic. On 32-bit, we don't do soft interrupt disabling, so this complication doesn't occur and there is no need to fall back to reading the Linux PTE, since hash_page (or the TLB miss handler) will get called automatically if necessary. Note that we cannot get PMU interrupts in the interval during context switch between switch_mm (which switches the user address space) and switch_to (which actually changes current to the new process). On 64-bit this is because interrupts are hard-disabled in switch_mm and stay hard-disabled until they are soft-enabled later, after switch_to has returned. So there is no possibility of trying to do a user stack trace when the user address space is not current's address space. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
| * | powerpc: Allow perf_counters to access user memory at interrupt timePaul Mackerras2009-08-184-12/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This provides a mechanism to allow the perf_counters code to access user memory in a PMU interrupt routine. Such an access can cause various kinds of interrupt: SLB miss, MMU hash table miss, segment table miss, or TLB miss, depending on the processor. This commit only deals with 64-bit classic/server processors, which use an MMU hash table. 32-bit processors are already able to access user memory at interrupt time. Since we don't soft-disable on 32-bit, we avoid the possibility of reentering hash_page or the TLB miss handlers, since they run with interrupts disabled. On 64-bit processors, an SLB miss interrupt on a user address will update the slb_cache and slb_cache_ptr fields in the paca. This is OK except in the case where a PMU interrupt occurs in switch_slb, which also accesses those fields. To prevent this, we hard-disable interrupts in switch_slb. Interrupts are already soft-disabled at this point, and will get hard-enabled when they get soft-enabled later. This also reworks slb_flush_and_rebolt: to avoid hard-disabling twice, and to make sure that it clears the slb_cache_ptr when called from other callers than switch_slb, the existing routine is renamed to __slb_flush_and_rebolt, which is called by switch_slb and the new version of slb_flush_and_rebolt. Similarly, switch_stab (used on POWER3 and RS64 processors) gets a hard_irq_disable() to protect the per-cpu variables used there and in ste_allocate. If a MMU hashtable miss interrupt occurs, normally we would call hash_page to look up the Linux PTE for the address and create a HPTE. However, hash_page is fairly complex and takes some locks, so to avoid the possibility of deadlock, we check the preemption count to see if we are in a (pseudo-)NMI handler, and if so, we don't call hash_page but instead treat it like a bad access that will get reported up through the exception table mechanism. An interrupt whose handler runs even though the interrupt occurred when soft-disabled (such as the PMU interrupt) is considered a pseudo-NMI handler, which should use nmi_enter()/nmi_exit() rather than irq_enter()/irq_exit(). Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
| * | powerpc/32: Always order writes to halves of 64-bit PTEsPaul Mackerras2009-08-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 32-bit systems with 64-bit PTEs, the PTEs have to be written in two 32-bit halves. On SMP we write the higher-order half and then the lower-order half, with a write barrier between the two halves, but on UP there was no particular ordering of the writes to the two halves. This extends the ordering that we already do on SMP to the UP case as well. The reason is that with the perf_counter subsystem potentially accessing user memory at interrupt time to get stack traces, we have to be careful not to create an incorrect but apparently valid PTE even on UP. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
* | | perf tools: Librarize trace_event() helperFrederic Weisbecker2009-08-1611-42/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Librarize trace_event() helper so that perf trace can use it too. Also clean up the debug.h includes a bit. It's not good to have it included in perf.h because it doesn't make it flexible against other headers it may need (headers that can also depend on perf.h and then create a recursive header dependency). Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250453149-664-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf tools: Librarize sample type and attr finding from headersFrederic Weisbecker2009-08-163-38/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Librarize the sample type and attr fetching from perf data file headers so that we can also use it from perf trace. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250448997-30715-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf tools: Put the show mode into the event headers filesFrederic Weisbecker2009-08-163-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Annotate and report share the same flags to filter events considering their context (kernel, user, hypervisor). Both tools have their own definitions of these flags. Factorize them out into the event headers file. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250445414-29237-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf tools: Factorize the dprintf definitionFrederic Weisbecker2009-08-164-51/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have two users of dprintf: report and annotate. Another one is coming with perf trace. Then factorize it into the debug file. While at it, rename dprintf() to dump_printf() so that it doesn't conflicts with its libc homograph. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250443461-28130-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf tools: Substract -Wformat-nonliteral from Wformat=2 in extra flagsFrederic Weisbecker2009-08-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The soon coming perf trace needs to use printf with dynamically built formats. But we are using -Wformat=2 which is a shortcut for the following set: -Wformat -Wformat-security -Wformat-y2k -Wformat-nonliteral -Wformat-nonliteral warns when it can't check formats because they are not builtin constant strings, but we want to feature dynamic formats. What we want instead is Wformat=2 minus -Wformat-nonliteral, which is what this patch does. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250437927-25490-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf: Build with stack-protector and with -D_FORTIFY_SOURCE=2Ingo Molnar2009-08-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up our defences a bit. Suggested-by: Arjan van de Ven <arjan@infradead.org> 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>
* | | perf: Enable more compiler warningsIngo Molnar2009-08-1622-148/+194
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Related to a shadowed variable bug fix Valdis Kletnieks noticed that perf does not get built with -Wshadow, which could have helped us avoid the bug. So enable -Wshadow and also enable the following warnings on perf builds, in addition to the already enabled -Wall -Wextra -std=gnu99 warnings: -Wcast-align -Wformat=2 -Wshadow -Winit-self -Wpacked -Wredundant-decls -Wstack-protector -Wstrict-aliasing=3 -Wswitch-default -Wswitch-enum -Wno-system-headers -Wundef -Wvolatile-register-var -Wwrite-strings -Wbad-function-cast -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wstrict-prototypes -Wdeclaration-after-statement And change/fix the perf code to build cleanly under GCC 4.3.2. The list of warnings enablement is rather arbitrary: it's based on my (quick) reading of the GCC manpages and trying them on perf. I categorized the warnings based on individually enabling them and looking whether they trigger something in the perf build. If i liked those warnings (i.e. if they trigger for something that arguably could be improved) i enabled the warning. If the warnings seemed to come from language laywers spamming the build with tons of nuisance warnings i generally kept them off. Most of the sign conversion related warnings were in this category. (A second patch enabling some of the sign warnings might be welcome - sign bugs can be nasty.) I also kept warnings that seem to make sense from their manpage description and which produced no actual warnings on our code base. These warnings might still be turned off if they end up being a nuisance. I also left out a few warnings that are not supported in older compilers. [ Note that these changes might break the build on older compilers i did not test, or on non-x86 architectures that produce different warnings, so more testing would be welcome. ] Reported-by: Valdis.Kletnieks@vt.edu 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>
* | | perf tools: Factorize the thread code in a dedicated fileFrederic Weisbecker2009-08-155-339/+202
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factorize the thread management code used by perf-annotate and perf-report in dedicated source and header files. v2: pass last_match by address so that it can actually be modified. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250245313-6995-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'perfcounters/urgent' into perfcounters/coreIngo Molnar2009-08-15140-639/+1398
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | Conflicts: kernel/perf_counter.c Merge reason: update to latest upstream (-rc6) and resolve the conflict with urgent fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | perf record: Fix typo in pid_synthesize_comm_eventArnaldo Carvalho de Melo2009-08-151-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | We were using 'fd' locally, but there was a global 'fd' too, so when converting from open to fopen the test made against fd should be made against 'fp', but since we have that global it didnt get discovered ... Reported-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090814182632.GF3490@ghostprotocols.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * Linux 2.6.31-rc6Linus Torvalds2009-08-131-1/+1
| |
| * genirq: prevent wakeup of freed irq threadLinus Torvalds2009-08-131-10/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | free_irq() can remove an irqaction while the corresponding interrupt is in progress, but free_irq() sets action->thread to NULL unconditionally, which might lead to a NULL pointer dereference in handle_IRQ_event() when the hard interrupt context tries to wake up the handler thread. Prevent this by moving the thread stop after synchronize_irq(). No need to set action->thread to NULL either as action is going to be freed anyway. This fixes a boot crash reported against preempt-rt which uses the mainline irq threads code to implement full irq threading. [ tglx: removed local irqthread variable ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * Merge branch 'perfcounters-fixes-for-linus' of ↵Linus Torvalds2009-08-1311-190/+429
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter: Report the cloning task as parent on perf_counter_fork() perf_counter: Fix an ipi-deadlock perf: Rework/fix the whole read vs group stuff perf_counter: Fix swcounter context invariance perf report: Don't show unresolved DSOs and symbols when -S/-d is used perf tools: Add a general option to enable raw sample records perf tools: Add a per tracepoint counter attribute to get raw sample perf_counter: Provide hw_perf_counter_setup_online() APIs perf list: Fix large list output by using the pager perf_counter, x86: Fix/improve apic fallback perf record: Add missing -C option support for specifying profile cpu perf tools: Fix dso__new handle() to handle deleted DSOs perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available perf report: Show the tid too in -D perf record: Fix .tid and .pid fill-in when synthesizing events perf_counter, x86: Fix generic cache events on P6-mobile CPUs perf_counter, x86: Fix lapic printk message
| | * perf_counter: Report the cloning task as parent on perf_counter_fork()Peter Zijlstra2009-08-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A bug in (9f498cc: perf_counter: Full task tracing) makes profiling multi-threaded apps it go belly up. [ output as: (PID:TID):(PPID:PTID) ] # ./perf report -D | grep FORK 0x4b0 [0x18]: PERF_EVENT_FORK: (3237:3237):(3236:3236) 0xa10 [0x18]: PERF_EVENT_FORK: (3237:3238):(3236:3236) 0xa70 [0x18]: PERF_EVENT_FORK: (3237:3239):(3236:3236) 0xad0 [0x18]: PERF_EVENT_FORK: (3237:3240):(3236:3236) 0xb18 [0x18]: PERF_EVENT_FORK: (3237:3241):(3236:3236) Shows us that the test (27d028d perf report: Update for the new FORK/EXIT events) in builtin-report.c: /* * A thread clone will have the same PID for both * parent and child. */ if (thread == parent) return 0; Will clearly fail. The problem is that perf_counter_fork() reports the actual parent, instead of the cloning thread. Fixing that (with the below patch), yields: # ./perf report -D | grep FORK 0x4c8 [0x18]: PERF_EVENT_FORK: (1590:1590):(1589:1589) 0xbd8 [0x18]: PERF_EVENT_FORK: (1590:1591):(1590:1590) 0xc80 [0x18]: PERF_EVENT_FORK: (1590:1592):(1590:1590) 0x3338 [0x18]: PERF_EVENT_FORK: (1590:1593):(1590:1590) 0x66b0 [0x18]: PERF_EVENT_FORK: (1590:1594):(1590:1590) Which both makes more sense and doesn't confuse perf report anymore. Reported-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: paulus@samba.org Cc: Anton Blanchard <anton@samba.org> Cc: Arjan van de Ven <arjan@infradead.org> LKML-Reference: <1250172882.5241.62.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf_counter: Fix an ipi-deadlockPeter Zijlstra2009-08-131-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_pending_counter() is called from IRQ context and will call perf_counter_disable(), however perf_counter_disable() uses smp_call_function_single() which doesn't fancy being used with IRQs disabled due to IPI deadlocks. Fix this by making it use the local __perf_counter_disable() call and teaching the counter_sched_out() code about pending disables as well. This should cover the case where a counter migrates before the pending queue gets processed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey J Ashford <cjashfor@us.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> LKML-Reference: <20090813103655.244097721@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf: Rework/fix the whole read vs group stuffPeter Zijlstra2009-08-132-83/+238
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace PERF_SAMPLE_GROUP with PERF_SAMPLE_READ and introduce PERF_FORMAT_GROUP to deal with group reads in a more generic way. This allows you to get group reads out of read() as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey J Ashford <cjashfor@us.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> LKML-Reference: <20090813103655.117411814@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf_counter: Fix swcounter context invariancePeter Zijlstra2009-08-131-26/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_swcounter_is_counting() uses a lock, which means we cannot use swcounters from NMI or when holding that particular lock, this is unintended. The below removes the lock, this opens up race window, but not worse than the swcounters already experience due to RCU traversal of the context in perf_swcounter_ctx_event(). This also fixes the hard lockups while opening a lockdep tracepoint counter. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> Cc: Corey J Ashford <cjashfor@us.ibm.com> LKML-Reference: <1250149915.10001.66.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf report: Don't show unresolved DSOs and symbols when -S/-d is usedArnaldo Carvalho de Melo2009-08-131-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're interested in just those symbols/DSOs, so filter out the unresolved ones. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090812211957.GE3495@ghostprotocols.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf tools: Add a general option to enable raw sample recordsFrederic Weisbecker2009-08-131-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While we can enable the perf sample records per tracepoint counter, we may also want to enable this option for every tracepoint counters to open, so that we don't need to add a :record flag for all of them. Add the -R, --raw-samples options for this purpose. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250152039-7284-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf tools: Add a per tracepoint counter attribute to get raw sampleFrederic Weisbecker2009-08-132-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new flag field while opening a tracepoint perf counter: -e tracepoint_subsystem:tracepoint_name:flags This is intended to be generic although for now it only supports the r[e[c[o[r[d]]]]] flag: ./perf record -e workqueue:workqueue_insertion:record ./perf record -e workqueue:workqueue_insertion:r will have the same effect: enabling the raw samples record for the given tracepoint counter. In the future, we may want to support further flags, separated by commas. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1250152039-7284-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf_counter: Provide hw_perf_counter_setup_online() APIsIngo Molnar2009-08-132-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide weak aliases for hw_perf_counter_setup_online(). This is used by the BTS patches (for v2.6.32), but it interacts with fixes so propagate this upstream. (it has no effect as of yet) Also export perf_counter_output() to architecture code. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf list: Fix large list output by using the pagerArnaldo Carvalho de Melo2009-08-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When /sys/kernel/debug is mounted the list can be imense, so use the pager like the other tools. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090812174459.GB3495@ghostprotocols.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf_counter, x86: Fix/improve apic fallbackIngo Molnar2009-08-122-5/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * perf record: Add missing -C option support for specifying profile cpuJens Axboe2009-08-121-3/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf top supports a -C for setting the profile CPU, but perf record does not. This adds the same option for perf record, allowing the user to specify a specific target profile CPU. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> 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: <20090812091801.GC12579@kernel.dk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf tools: Fix dso__new handle() to handle deleted DSOsArnaldo Carvalho de Melo2009-08-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is better than showing the map addr, this way at least we know that we can't get the symtabs because the DSO was deleted (system update) while an app still used such DSO. Yeah, don't do that, but if you do, you'll figure it out quicker this way. [acme@doppio linux-2.6-tip]$ perf report | head -15 # Samples: 3796 # # Overhead Command Shared Object Symbol # ........ ....... ................................................................... ...... # 23.55% pidgin /lib64/libglib-2.0.so.0.2000.4.#prelink#.Pd98lu (deleted) [.] 0x00000000038844 21.55% pidgin /lib64/libpthread-2.10.1.so.#prelink#.AFwK8Q (deleted) [.] 0x0000000000a42d 10.85% pidgin [kernel] [.] vread_hpet 7.85% pidgin /lib64/libgobject-2.0.so.0.2000.4.#prelink#.o1vpU7 (deleted) [.] 0x00000000014de8 3.35% pidgin /lib64/libc-2.10.1.so (deleted) [.] 0x0000000007a875 3.19% pidgin /lib64/libdbus-1.so.3.4.0.#prelink#.6mwgZP (deleted) [.] 0x0000000001d254 3.06% pidgin /usr/lib64/libgtk-x11-2.0.so.0.1600.5.#prelink#.511hAl (deleted) [.] 0x000000002334e7 2.90% pidgin /usr/lib64/libgdk-x11-2.0.so.0.1600.5.#prelink#.5qlMo1 (deleted) [.] 0x00000000037b2d 1.84% pidgin [kernel] [k] do_sys_poll 1.45% pidgin /usr/lib64/libX11.so.6.2.0.#prelink#.iR59Rx (deleted) [.] 0x0000000004c751 [acme@doppio linux-2.6-tip]$ Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Luis Claudio R. Gonçalves <lclaudio@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Frédéric Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090811200436.GA3478@ghostprotocols.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not ↵Arnaldo Carvalho de Melo2009-08-123-26/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | available In old binutils we can't access bfd_demangle(), use cplus_demangle() just like oprofile. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Luis Claudio R. Gonçalves <lclaudio@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Frédéric Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090811192211.GG18061@ghostprotocols.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf report: Show the tid too in -DArnaldo Carvalho de Melo2009-08-121-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This made it easier to find the firefox threading related bug. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Frédéric Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090811192138.GE18061@ghostprotocols.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf record: Fix .tid and .pid fill-in when synthesizing eventsArnaldo Carvalho de Melo2009-08-121-33/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Noticed when trying to record events for a firefox thread. We were synthesizing both .tid and .pid with the pid passed via --pid. Fix it by reading /proc/PID/status and getting the tgid to use in .pid, .tid gets the specified "pid". Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20090811192200.GF18061@ghostprotocols.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * perf_counter, x86: Fix generic cache events on P6-mobile CPUsIngo Molnar2009-08-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Johannes Stezenbach reported that 'perf stat' does not count cache-miss and cache-references events on his Pentium-M based laptop. This is because we left them blank in p6_perfmon_event_map[], fill them in. 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>
| | * perf_counter, x86: Fix lapic printk messageIngo Molnar2009-08-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of this garbled bootup on UP Pentium-M systems: [ 0.015048] Performance Counters: [ 0.016004] no Local APIC, try rebooting with lapicno PMU driver, software counters only. Print: [ 0.015050] Performance Counters: [ 0.016004] no APIC, boot with the "lapic" boot parameter to force-enable it. [ 0.017003] no PMU driver, software counters only. Cf: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> 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>
| * | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2009-08-134-11/+37
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: futex: Fix handling of bad requeue syscall pairing futex: Fix compat_futex to be same as futex for REQUEUE_PI locking, sched: Give waitqueue spinlocks their own lockdep classes futex: Update futex_q lock_ptr on requeue proxy lock
| | * | futex: Fix handling of bad requeue syscall pairingDarren Hart2009-08-101-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If futex_requeue(requeue_pi=1) finds a futex_q that was created by a call other the futex_wait_requeue_pi(), the q.rt_waiter may be null. If so, this will result in an oops from the following call graph: futex_requeue() rt_mutex_start_proxy_lock() task_blocks_on_rt_mutex() waiter->task dereference OOPS We currently WARN_ON() if this is detected, clearly this is inadequate. If we detect a mispairing in futex_requeue(), bail out, seding -EINVAL to user-space. V2: Fix parenthesis warnings. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: John Kacur <jkacur@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@linux.vnet.ibm.com> LKML-Reference: <4A7CA8C0.7010809@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | futex: Fix compat_futex to be same as futex for REQUEUE_PIDinakar Guniguntala2009-08-101-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Need to add the REQUEUE_PI checks to the compat_sys_futex API as well to ensure 32 bit requeue's work fine on a 64 bit system. Patch is against latest tip Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Cc: Darren Hart <dvhltc@us.ibm.com> LKML-Reference: <20090810130142.GA23619@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | locking, sched: Give waitqueue spinlocks their own lockdep classesPeter Zijlstra2009-08-102-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Give waitqueue spinlocks their own lockdep classes when they are initialised from init_waitqueue_head(). This means that struct wait_queue::func functions can operate other waitqueues. This is used by CacheFiles to catch the page from a backing fs being unlocked and to wake up another thread to take a copy of it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Takashi Iwai <tiwai@suse.de> Cc: linux-cachefs@redhat.com Cc: torvalds@osdl.org Cc: akpm@linux-foundation.org LKML-Reference: <20090810113305.17284.81508.stgit@warthog.procyon.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | futex: Update futex_q lock_ptr on requeue proxy lockDarren Hart2009-08-101-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | futex_requeue() can acquire the lock on behalf of a waiter early on or during the requeue loop if it is uncontended or in the event of a lock steal or owner died. On wakeup, the waiter (in futex_wait_requeue_pi()) cleans up the pi_state owner using the lock_ptr to protect against concurrent access to the pi_state. The pi_state is hung off futex_q's on the requeue target futex hash bucket so the lock_ptr needs to be updated accordingly. The problem manifested by triggering the WARN_ON in lookup_pi_state() about the pid != pi_state->owner->pid. With this patch, the pi_state is properly guarded against concurrent access via the requeue target hb lock. The astute reviewer may notice that there is a window of time between when futex_requeue() unlocks the hb locks and when futex_wait_requeue_pi() will acquire hb2->lock. During this time the pi_state and uval are not in sync with the underlying rtmutex owner (but the uval does indicate there are waiters, so no atomic changes will occur in userspace). However, this is not a problem. Should a contending thread enter lookup_pi_state() and acquire hb2->lock before the ownership is fixed up, it will find the pi_state hung off a waiter's (possibly the pending owner's) futex_q and block on the rtmutex. Once futex_wait_requeue_pi() fixes up the owner, it will also move the pi_state from the old owner's task->pi_state_list to its own. v3: Fix plist lock name for application to mainline (rather than -rt) Compile tested against tip/v2.6.31-rc5. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@linux.vnet.ibm.com> LKML-Reference: <4A7F4EFF.6090903@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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