From 39e6dd73502f64e2ae3236b304e160ae30de9384 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 14 Aug 2009 15:26:32 -0300 Subject: [PATCH 1/6] perf record: Fix typo in pid_synthesize_comm_event 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 Signed-off-by: Arnaldo Carvalho de Melo Cc: Peter Zijlstra LKML-Reference: <20090814182632.GF3490@ghostprotocols.net> Signed-off-by: Ingo Molnar --- tools/perf/builtin-record.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 3d051b9cf25..89a5ddcd1de 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -219,7 +219,7 @@ static pid_t pid_synthesize_comm_event(pid_t pid, int full) snprintf(filename, sizeof(filename), "/proc/%d/status", pid); fp = fopen(filename, "r"); - if (fd == NULL) { + if (fp == NULL) { /* * We raced with a task exiting - just return: */ From 2932cffc89e9a1476b28a59896fa4f81e0d4f131 Mon Sep 17 00:00:00 2001 From: "Carlos R. Mafra" Date: Mon, 17 Aug 2009 00:36:21 +0200 Subject: [PATCH 2/6] perf: Rename perf-examples.txt to examples.txt 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 Cc: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: Signed-off-by: Ingo Molnar --- tools/perf/Documentation/{perf-examples.txt => examples.txt} | 0 1 file changed, 0 insertions(+), 0 deletions(-) rename tools/perf/Documentation/{perf-examples.txt => examples.txt} (100%) diff --git a/tools/perf/Documentation/perf-examples.txt b/tools/perf/Documentation/examples.txt similarity index 100% rename from tools/perf/Documentation/perf-examples.txt rename to tools/perf/Documentation/examples.txt From e1ac3614ff606ae03677f47459113f98a19af63c Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Fri, 14 Aug 2009 15:39:10 +1000 Subject: [PATCH 3/6] perf_counter: Check task on counter read IPI 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 Acked-by: Peter Zijlstra LKML-Reference: <19076.63614.277861.368125@drongo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 534e20d14d6..b8fe7397b90 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1503,10 +1503,21 @@ static void perf_counter_enable_on_exec(struct task_struct *task) */ static void __perf_counter_read(void *info) { + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_counter *counter = info; struct perf_counter_context *ctx = counter->ctx; unsigned long flags; + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. In that case + * counter->count would have been updated to a recent sample + * when the counter was scheduled out. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + local_irq_save(flags); if (ctx->is_active) update_context_time(ctx); From f738eb1b63edf664da1b4ac76895d988749b2f07 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 18 Aug 2009 11:32:24 +0200 Subject: [PATCH 4/6] perf_counter: Fix the PARISC build 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 Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index b8fe7397b90..36f65e2b8b5 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -2019,6 +2019,10 @@ int perf_counter_task_disable(void) return 0; } +#ifndef PERF_COUNTER_INDEX_OFFSET +# define PERF_COUNTER_INDEX_OFFSET 0 +#endif + static int perf_counter_index(struct perf_counter *counter) { if (counter->state != PERF_COUNTER_STATE_ACTIVE) From 15f3fa4e7f608c5ce19187b3b4a953222fdfa751 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 18 Aug 2009 13:52:28 +0200 Subject: [PATCH 5/6] perf annotate: Fix segmentation fault Linus reported this perf annotate segfault: [torvalds@nehalem git]$ perf annotate unmap_vmas Segmentation fault #0 map__clone (self=) at builtin-annotate.c:236 #1 thread__fork (self=) 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 Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- tools/perf/builtin-annotate.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c index 1dba568e194..343e7b14bf0 100644 --- a/tools/perf/builtin-annotate.c +++ b/tools/perf/builtin-annotate.c @@ -980,6 +980,13 @@ process_fork_event(event_t *event, unsigned long offset, unsigned long head) (void *)(long)(event->header.size), event->fork.pid, event->fork.ppid); + /* + * A thread clone will have the same PID for both + * parent and child. + */ + if (thread == parent) + return 0; + if (!thread || !parent || thread__fork(thread, parent)) { dprintf("problem processing PERF_EVENT_FORK, skipping event.\n"); return -1; From b395cd8a74b4a8d943dd4b5585e676f62f7350b3 Mon Sep 17 00:00:00 2001 From: Kyle McMartin Date: Tue, 18 Aug 2009 12:41:25 -0400 Subject: [PATCH 6/6] perf tools: Make 'make html' work 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 Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: <20090818164125.GM25206@bombadil.infradead.org> Signed-off-by: Ingo Molnar --- tools/perf/Documentation/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/Documentation/Makefile b/tools/perf/Documentation/Makefile index 5457192e1b4..bdd3b7ecad0 100644 --- a/tools/perf/Documentation/Makefile +++ b/tools/perf/Documentation/Makefile @@ -35,7 +35,7 @@ man7dir=$(mandir)/man7 # DESTDIR= ASCIIDOC=asciidoc -ASCIIDOC_EXTRA = +ASCIIDOC_EXTRA = --unsafe MANPAGE_XSL = manpage-normal.xsl XMLTO_EXTRA = INSTALL?=install