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* perf_counter: Report the cloning task as parent on perf_counter_fork()Peter Zijlstra2009-08-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Zijlstra2009-08-13
| | | | | | | | | | | | | | | | | | | | | 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 Zijlstra2009-08-13
| | | | | | | | | | | | | | | 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 Zijlstra2009-08-13
| | | | | | | | | | | | | | | | | | | | | 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 Melo2009-08-13
| | | | | | | | | | 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 Weisbecker2009-08-13
| | | | | | | | | | | | | | | | 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 Weisbecker2009-08-13
| | | | | | | | | | | | | | | | | | | | | | | | | 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 Molnar2009-08-13
| | | | | | | | | | | | | | 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 Melo2009-08-13
| | | | | | | | | | | 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 Molnar2009-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Axboe2009-08-12
| | | | | | | | | | | | | | | 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 Melo2009-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Melo2009-08-12
| | | | | | | | | | | | | | | | 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 Melo2009-08-12
| | | | | | | | | | | | | 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 Melo2009-08-12
| | | | | | | | | | | | | | | | | 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 Molnar2009-08-11
| | | | | | | | | | | | | | | | | | 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 Molnar2009-08-11
| | | | | | | | | | | | | | | | | | | | | 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>
* pty: fix data loss when stopped (^S/^Q)Linus Torvalds2009-08-10
| | | | | | | | | | | | | | | | | | | | | Commit d945cb9cc ("pty: Rework the pty layer to use the normal buffering logic") dropped the test for 'tty->stopped' in pty_write_room(), which then causes the n_tty line discipline thing to not throttle the data properly when the tty is stopped. So instead of pausing the write due to the tty being stopped, the ldisc layer would go ahead and push it down to the pty. The pty write() routine would then refuse to take the data (because it _did_ check 'stopped'), and the data wouldn't actually be written. This whole stopped test should eventually be moved into the tty ldisc layer rather than have low-level tty drivers care about these things, but right now the fix is to just re-instate the missing pty 'stopped' handling. Reported-and-tested-by: Artur Skawina <art.08.09@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'perfcounters-fixes-for-linus' of ↵Linus Torvalds2009-08-10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: (27 commits) perf_counter: Zero dead bytes from ftrace raw samples size alignment perf_counter: Subtract the buffer size field from the event record size perf_counter: Require CAP_SYS_ADMIN for raw tracepoint data perf_counter: Correct PERF_SAMPLE_RAW output perf tools: callchain: Fix bad rounding of minimum rate perf_counter tools: Fix libbfd detection for systems with libz dependency perf: "Longum est iter per praecepta, breve et efficax per exempla" perf_counter: Fix a race on perf_counter_ctx perf_counter: Fix tracepoint sampling to be part of generic sampling perf_counter: Work around gcc warning by initializing tracepoint record unconditionally perf tools: callchain: Fix sum of percentages to be 100% by displaying amount of ignored chains in fractal mode perf tools: callchain: Fix 'perf report' display to be callchain by default perf tools: callchain: Fix spurious 'perf report' warnings: ignore empty callchains perf record: Fix the -A UI for empty or non-existent perf.data perf util: Fix do_read() to fail on EOF instead of busy-looping perf list: Fix the output to not include tracepoints without an id perf_counter/powerpc: Fix oops on cpus without perf_counter hardware support perf stat: Fix tool option consistency: rename -S/--scale to -c/--scale perf report: Add debug help for the finding of symbol bugs - show the symtab origin (DSO, build-id, kernel, etc) perf report: Fix per task mult-counter stat reporting ...
| * perf_counter: Zero dead bytes from ftrace raw samples size alignmentFrederic Weisbecker2009-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After aligning the ftrace raw samples, there are dead bytes storing random data from the stack. We don't want to leak these to userspace, then zero these out. Before: 0x2de88 [0x50]: event: 9 . . ... raw event: size 80 bytes . 0000: 09 00 00 00 01 00 50 00 d0 c7 00 81 ff ff ff ff ......P........ . 0010: 68 01 00 00 68 01 00 00 2c 00 00 00 00 00 00 00 h...h...,...... . 0020: 2c 00 00 00 2b 00 01 02 68 01 00 00 68 01 00 00 ,...+...h...h.. . 0030: 6b 6f 6e 64 65 6d 61 6e 64 2f 30 00 00 00 00 00 kondemand/0.... . 0040: 68 01 00 00 40 7f 46 81 ff ff ff ff 00 10 1b 7f h...@.F........ ^ ^ ^ ^ Leak After: 0x2d318 [0x50]: event: 9 . . ... raw event: size 80 bytes . 0000: 09 00 00 00 01 00 50 00 d0 c7 00 81 ff ff ff ff ......P........ . 0010: 68 01 00 00 68 01 00 00 68 14 00 00 00 00 00 00 h...h...h...... . 0020: 2c 00 00 00 2b 00 01 02 68 01 00 00 68 01 00 00 ,...+...h...h.. . 0030: 6b 6f 6e 64 65 6d 61 6e 64 2f 30 00 00 00 00 00 kondemand/0.... . 0040: 68 01 00 00 a0 80 46 81 ff ff ff ff 00 00 00 00 h.....F........ ^ ^ ^ ^ Fixed Reported-by: Peter Zijlstra <peterz@infradead.org> 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: <1249915116-5210-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de>
| * perf_counter: Subtract the buffer size field from the event record sizeFrederic Weisbecker2009-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We compute the perf raw sample size by aligning the raw ftrace event size plus the buffer size field itself. We do that instead of aligning only the perf raw sample size, so that we might economize some in some cases. But this buffer size field is not stored in the perf raw sample, we must then substract its size from the buffer once we computed the alignment unless we may get a useless u32 field in the buffer. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20090810141129.GA5124@nowhere> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter: Require CAP_SYS_ADMIN for raw tracepoint dataPeter Zijlstra2009-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | Raw tracepoint data contains various kernel internals and data from other users, so restrict this to CAP_SYS_ADMIN. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249896452.17467.75.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter: Correct PERF_SAMPLE_RAW outputPeter Zijlstra2009-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | PERF_SAMPLE_* output switches should unconditionally output the correct format, as they are the only way to unambiguously parse the PERF_EVENT_SAMPLE data. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249896447.17467.74.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: callchain: Fix bad rounding of minimum rateFrederic Weisbecker2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes we get callchain branches that have a rate under the limit given by the user. Say you launched: perf record -f -g -a ./hackbench 10 perf report -g fractal,10.0 And you got: 2.33% hackbench [kernel] [k] _spin_lock_irqsave | |--78.57%-- remove_wait_queue | poll_freewait | do_sys_poll | sys_poll | sysenter_dispatch | 0xf7ffa430 | 0x1ffadea3c | |--7.14%-- __up_read | up_read | do_page_fault | page_fault | 0xf7ffa430 | 0xa0df710000000a ... It is abnormal to get a 7.14% branch whereas we passed a 10% filter. The problem is that we round down the minimum threshold. This happens mostly when we have very low number of events. If the total amount of your branch is 4 and you have a subranch of 3 events, filtering to 90% will be computed like follows: limit = 4 * 0.9; The result is about 3.6, but the cast to integer will round down to 3. It means that our filter is actually of 75% We must then explicitly round up the minimum threshold. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: acme@redhat.com Cc: peterz@infradead.org Cc: efault@gmx.de LKML-Reference: <20090809024235.GA10146@nowhere> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter tools: Fix libbfd detection for systems with libz dependencyMike Galbraith2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to a libz dependency in some distro's binutils package, C++ demangle support isn't compiled in despite the necessary libraries being available. Fix this by adding a -lz link test to the dependency detection rules. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1249733655.6929.5.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf: "Longum est iter per praecepta, breve et efficax per exempla"Carlos R. Mafra2009-08-09
| | | | | | | | | | | | | | | | | | | | | | A few examples of how 'perf' can be used, from an e-mail by Ingo Molnar http://lkml.org/lkml/2009/8/4/346. Signed-off-by: Carlos R. Mafra <crmafra2@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <20090805185334.GA4535@Pilar.aei.mpg.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter: Fix a race on perf_counter_ctxPeter Zijlstra2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While extending perfcounters with BTS hw-tracing, Markus Metzger managed to trigger this warning: [ 995.557128] WARNING: at kernel/perf_counter.c:1191 __perf_counter_task_sched_out+0x48/0x6b() triggers because commit 9f498cc5be7e013d8d6e4c616980ed0ffc8680d2 (perf_counter: Full task tracing) removed clearing of tsk->perf_counter_ctxp out from under ctx->lock which introduced a race (against perf_lock_task_context). Move it back and deal with the exit notification by explicitly passing along the former task context. Reported-by: Markus T Metzger <markus.t.metzger@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249667341.17467.5.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter: Fix tracepoint sampling to be part of generic samplingFrederic Weisbecker2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on Peter's comments, make tracepoint sampling generic just like all the other sampling bits are. This is a rename with no code changes: - PERF_SAMPLE_TP_RECORD to PERF_SAMPLE_RAW - struct perf_tracepoint_record to perf_raw_record We want the system in place that transport tracepoints raw samples events into the perf ring buffer to be generalized and usable by any type of counter. Reported-by; Peter Zijlstra <peterz@infradead.org> 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> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249698400-5441-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter: Work around gcc warning by initializing tracepoint record ↵Frederic Weisbecker2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | unconditionally Despite that the tracepoint record is always present when the PERF_SAMPLE_TP_RECORD flag is set, gcc raises a warning, thinking it might not be initialized: kernel/perf_counter.c: In function ‘perf_counter_output’: kernel/perf_counter.c:2650: warning: ‘tp’ may be used uninitialized in this function Then, initialize it to NULL and always check if it's not NULL before dereference it. Reported-by: Ingo Molnar <mingo@elte.hu> 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> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249698400-5441-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: callchain: Fix sum of percentages to be 100% by displaying ↵Frederic Weisbecker2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | amount of ignored chains in fractal mode When we filter the callchains below a given percentage, we ignore them and the end result only shows entries that have an upper percentage than the filter threshold. It seems to users then that we have an imbalance in the percentage, as if the sum inside a profiled branch doesn't reach 100%. Since in the past there have been real perf report bugs that showed the same sypmtom, it would be nice to assure the user that the data is perfect and trustable and it all sums up to 100.00%. So fix this by displaying the remaining hits that have been filtered but without more detail than their amount in each branches. Example while filtering below 50%: 7.73% [k] delay_tsc | |--98.22%-- __const_udelay | | | |--86.37%-- ath5k_hw_register_timeout | | ath5k_hw_noise_floor_calibration | | ath5k_hw_reset | | ath5k_reset | | ath5k_config | | ieee80211_hw_config | | | | | |--88.53%-- ieee80211_scan_work | | | worker_thread | | | kthread | | | child_rip | | --11.47%-- [...] | --13.63%-- [...] --1.78%-- [...] Reported-by: Ingo Molnar <mingo@elte.hu> 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: <1249690585-9145-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: callchain: Fix 'perf report' display to be callchain by defaultFrederic Weisbecker2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we recorded with -g option to record the callchain, right now we require a -g option to perf report as well - and people reported this as unnecessary complication: the user already specified -g once, no need to require it a second time. So if the recording includes call-chains, display the callchain by default from perf report. ( The user can override this default using "-g none" option from perf report. ) Reported-by: Ingo Molnar <mingo@elte.hu> 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: <1249690585-9145-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: callchain: Fix spurious 'perf report' warnings: ignore empty ↵Frederic Weisbecker2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | callchains When the callchain tree comes to insert an empty backtrace, it raises a spurious warning about the fact we are inserting an empty. This is spurious because the radix tree assumes it did something wrong to reach this state. But it didn't, we just met an empty callchain that has to be ignored. This happens occasionally with certain types of call-chain recordings. If it happens it's a big nuisance as perf report output starts with thousands of warning lines. Reported-by: Ingo Molnar <mingo@elte.hu> 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: <1249690585-9145-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf record: Fix the -A UI for empty or non-existent perf.dataPierre Habouzit2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. Ignore the -A argument if there is no perf.data file 2. Treat an empty file like a non existent file. Else, perf will try to read the perf.data header, and fail with an error. Treating an empty file like a non-existent file makes sense, since an interupted (as in SIGKILLed) perf could leave such files around, and you don't want to annoy the user with errors for files with no data in it. Signed-off-by: Pierre Habouzit <pierre.habouzit@intersec.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf util: Fix do_read() to fail on EOF instead of busy-loopingPierre Habouzit2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While toying with perf, I've noticed that perf record can easily enter a busy loop when doing something as silly as: $ perf record -A ls Yeah, do_read here really wants to read a known size, not being able to should die(), not busy-loop ;) That was the cause for the bug. Signed-off-by: Pierre Habouzit <pierre.habouzit@intersec.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf list: Fix the output to not include tracepoints without an idPeter Zijlstra2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | Stop perf list from displaying tracepoints without an id file, those are special tracepoints that are not interfaced to perfcounters so listing them is erroneous and passing them as events will produce no output. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Jason Baron <jbaron@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter/powerpc: Fix oops on cpus without perf_counter hardware supportPaul Mackerras2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we have the powerpc perf_counter backend compiled in, but the cpu we are running on is one where we don't support the PMU, we currently oops in hw_perf_group_sched_in if we try to use any counters, because ppmu is NULL in that case, and we unconditionally dereference ppmu. This fixes the problem by adding a check if ppmu is NULL at the beginning of hw_perf_group_sched_in, and also at the beginning of the other functions that get called from the perf_counter core, i.e. hw_perf_disable, hw_perf_enable, and hw_perf_counter_setup. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: benh@kernel.crashing.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf stat: Fix tool option consistency: rename -S/--scale to -c/--scaleBrice Goglin2009-08-09
| | | | | | | | | | | | | | | | | | | | We want to use a coherent flag for -S/--stat across all tools, so free up -S in perf stat. Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf report: Add debug help for the finding of symbol bugs - show the symtab ↵Arnaldo Carvalho de Melo2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | origin (DSO, build-id, kernel, etc) Used with perf report --verbose: [acme@doppio linux-2.6-tip]$ perf report -v | head -16 5.17% firefox /usr/lib64/xulrunner-1.9.1/libxul.so 0x00000000005d8eee f [.] imgContainer::DrawFrameTo(gfxIImageFrame*, gfxIImageFrame*, nsRect&) 2.56% firefox /lib64/libpthread-2.10.1.so 0x0000000000008e02 d [.] __pthread_mutex_lock_internal 1.94% firefox /usr/lib64/xulrunner-1.9.1/libxul.so 0x0000000000d0af8f f [.] SearchTable 1.75% firefox [kernel] 0xffffffffff60013b k [.] vread_hpet 1.63% firefox /lib64/libpthread-2.10.1.so 0x000000000000a404 d [.] __pthread_mutex_unlock 1.47% firefox /usr/lib64/xulrunner-1.9.1/libmozjs.so 0x00000000000482ea f [.] js_Interpret 1.42% firefox /usr/lib64/xulrunner-1.9.1/libmozjs.so 0x000000000003eda3 f [.] JS_CallTracer 1.24% firefox [kernel] 0xffffffff8102ca4a k [k] read_hpet 1.16% firefox [kernel] 0xffffffff810f3dd4 k [k] fget_light 1.11% firefox /usr/lib64/xulrunner-1.9.1/libmozjs.so 0x00000000000567ff f [.] js_TraceObject 0.98% firefox /usr/lib64/firefox-3.5.2/firefox 0x000000000000dd23 b [.] arena_ralloc [acme@doppio linux-2.6-tip]$ The new field is just after the symbol address. To help in figuring out symbol resolution bugs. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf report: Fix per task mult-counter stat reportingPeter Zijlstra2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Brice Goglin reported: > I can easily sort them by thread id, but I don't know how to match > my 4 events with each group of 4 lines. Also report the counter id and the time running/enabled stats (in case the counter got time-shared). Reported-by: Brice Goglin <Brice.Goglin@inria.fr> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Brice Goglin <Brice.Goglin@inria.fr> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: Fix multi-counter stat bug caused by incorrect reading of ↵Peter Zijlstra2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf.data file header Brice Goglin reported that only the first result from a multi-counter perf record --stat run is accurate, the rest looks bogus. A silly mistake made us re-read the first attribute for every recorded attribute. Reported-by: Brice Goglin <Brice.Goglin@inria.fr> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Brice Goglin <Brice.Goglin@inria.fr> Cc: paulus@samba.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf tools: Fix call-chain cumul hit based sub-total (fractal mode)Frederic Weisbecker2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The callchain fractal mode builds each new total hits in a new branch of profiling by using the parent's hits of the current branch plus the hits of the children. This is wrong, the total hits of a branch should be made of the sum of every children hits, we must ignore the parent hits in this scope. This patch also fixes another mistake with the hit counting. Now the rates are correct. 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> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf top: Update man pageMike Galbraith2009-08-09
| | | | | | | | | | | | | | | | | | perf_counter tools: update perf top manual page to reflect current implementation. Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf top: Improve interactive key handlingMike Galbraith2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pressing any key which is not currently mapped to functionality, based on startup command line options, displays currently mapped keys, and prompts for input. Pressing any unmapped key at the prompt returns the user to display mode with variables unchanged. eg, pressing ? <SPACE> <ESC> etc displays currently available keys, the value of the variable associated with that key, and prompts. Pressing same again aborts input. Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter: Fix software counters for fast moving event sourcesPeter Zijlstra2009-08-09
| | | | | | | | | | | | | | | | | | | | | | Reimplement the software counters to deal with fast moving event sources (such as tracepoints). This means being able to generate multiple overflows from a single 'event' as well as support throttling. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter tools: Allow perf top top users to switch between weighted and ↵Mike Galbraith2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | individual counter display Add [w]eighted hotkey. Pressing [w] toggles between displaying weighted total of all counters, and the counter selected via [E]vent select key. ------------------------------------------------------------------------------ PerfTop: 90395 irqs/sec kernel:16.1% [cache-misses/cache-references/instructions], (all, 4 CPUs) ------------------------------------------------------------------------------ weight samples pcnt RIP kernel function ______ _______ _____ ________________ _______________ 1275408.6 10881 - 5.3% - ffffffff81146f70 : copy_page_c 553683.4 43569 - 21.3% - ffffffff81146f20 : clear_page_c 74075.0 6768 - 3.3% - ffffffff81147190 : copy_user_generic_string 40602.9 7538 - 3.7% - ffffffff81284ba2 : _spin_lock 26882.1 965 - 0.5% - ffffffff8109d280 : file_ra_state_init [w] ------------------------------------------------------------------------------ PerfTop: 91221 irqs/sec kernel:14.5% [10000Hz cache-misses], (all, 4 CPUs) ------------------------------------------------------------------------------ weight samples pcnt RIP kernel function ______ _______ _____ ________________ _______________ 47320.00 - 22.3% - ffffffff81146f20 : clear_page_c 14261.00 - 6.7% - ffffffff810992f5 : __rmqueue 11046.00 - 5.2% - ffffffff81146f70 : copy_page_c 7842.00 - 3.7% - ffffffff81284ba2 : _spin_lock 7234.00 - 3.4% - ffffffff810aa1d6 : unmap_vmas Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_counter tools: Fix/resurrect perf top annotation in a simple ↵Mike Galbraith2009-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | interactive form perf top used to have annotation support, but it has bitrotted and removed. This patch restores that: it allows the user to select any symbol in kernel space for source level annotation on the fly, switch between event counters and alter display variables. When symbol details are being displayed, stopping annotation reverts to normal. known keys: [d] select display delay. [e] select display entries (lines). [E] select annotation event counter. [f] select normal display count filter. [F] select annotation display count filter (percentage). [qQ] quit. [s] select annotation symbol and start annotation. [S] stop annotation, revert to normal display. [z] toggle event count zeroing. Sample: ------------------------------------------------------------------------------ PerfTop: 16719 irqs/sec kernel:78.7% [cache-misses/cache-references/instructions/cycles], (all, 4 CPUs) ------------------------------------------------------------------------------ Showing cache-misses for e1000_clean_rx_irq Events Pcnt (>=3%) 0 0.0% /* adjust length to remove Ethernet CRC */ 0 0.0% if (!(adapter->flags2 & FLAG2_CRC_STRIPPING)) 0 0.0% length -= 4; 436 5.0% f039: 41 f6 84 24 5c 29 00 testb $0x1,0x295c(%r12) 0 0.0% f089: 8b 4d 84 mov -0x7c(%rbp),%ecx 0 0.0% f08c: 48 83 ef 02 sub $0x2,%rdi 0 0.0% f090: 48 83 ee 02 sub $0x2,%rsi 811 9.3% f094: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 0 0.0% 0 0.0% while (rx_desc->status & E1000_RXD_STAT_DD) { 0 0.0% f114: 41 f6 47 0c 01 testb $0x1,0xc(%r15) 7226 82.6% f119: 0f 85 24 fe ff ff jne ef43 <e1000_clean_rx_irq+0x84> Available events: 0 cache-misses 1 cache-references 2 instructions 3 cycles Enter details event counter: 2 ------------------------------------------------------------------------------ PerfTop: 15035 irqs/sec kernel:79.0% [cache-misses/cache-references/instructions/cycles], (all, 4 CPUs) ------------------------------------------------------------------------------ Showing instructions for e1000_clean_rx_irq Events Pcnt (>=3%) 0 0.0% int *work_done, int work_to_do) 0 0.0% { 175 0.9% eebf: 55 push %rbp 1898 9.8% eec0: 48 89 e5 mov %rsp,%rbp 0 0.0% 0 0.0% i = rx_ring->next_to_clean; 140 0.7% ef0a: 0f b7 41 1a movzwl 0x1a(%rcx),%eax 670 3.4% ef0e: 89 45 ac mov %eax,-0x54(%rbp) 0 0.0% { 0 0.0% memcpy(skb->data + offset, from, len); 91 0.5% f07b: 49 8b b6 e8 00 00 00 mov 0xe8(%r14),%rsi 1153 5.9% f082: 48 8b b8 e8 00 00 00 mov 0xe8(%rax),%rdi 42 0.2% f089: 8b 4d 84 mov -0x7c(%rbp),%ecx 14 0.1% f08c: 48 83 ef 02 sub $0x2,%rdi 0 0.0% f090: 48 83 ee 02 sub $0x2,%rsi 1618 8.3% f094: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 0 0.0% 0 0.0% /* return some buffers to hardware, one at a time is too slow */ 0 0.0% if (cleaned_count >= E1000_RX_BUFFER_WRITE) { 867 4.5% f0e7: 83 7d b0 0f cmpl $0xf,-0x50(%rbp) 0 0.0% 0 0.0% while (rx_desc->status & E1000_RXD_STAT_DD) { 37 0.2% f114: 41 f6 47 0c 01 testb $0x1,0xc(%r15) 4047 20.8% f119: 0f 85 24 fe ff ff jne ef43 <e1000_clean_rx_irq+0x84> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds2009-08-10
|\ \ | | | | | | | | | | | | | | | | | | 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: Fix move_irq_desc() for nodes without ram
| * | x86/irq: Fix move_irq_desc() for nodes without ramYinghai Lu2009-08-08
| | | | | | | | | | | | | | | | | | | | | | | | Don't move it if target node is -1. Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <4A785B5D.4070702@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-08-10
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | 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: Fix serialization in pit_expect_msb()
| * | | x86: Fix serialization in pit_expect_msb()Linus Torvalds2009-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wei Chong Tan reported a fast-PIT-calibration corner-case: | pit_expect_msb() is vulnerable to SMI disturbance corner case | in some platforms which causes /proc/cpuinfo to show wrong | CPU MHz value when quick_pit_calibrate() jumps to success | section. I think that the real issue isn't even an SMI - but the fact that in the very last iteration of the loop, there's no serializing instruction _after_ the last 'rdtsc'. So even in the absense of SMI's, we do have a situation where the cycle counter was read without proper serialization. The last check should be done outside the outer loop, since _inside_ the outer loop, we'll be testing that the PIT has the right MSB value has the right value in the next iteration. So only the _last_ iteration is special, because that's the one that will not check the PIT MSB value any more, and because the final 'get_cycles()' isn't serialized. In other words: - I'd like to move the PIT MSB check to after the last iteration, rather than in every iteration - I think we should comment on the fact that it's also a serializing instruction and so 'fences in' the TSC read. Here's a suggested replacement. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: "Tan, Wei Chong" <wei.chong.tan@intel.com> Tested-by: "Tan, Wei Chong" <wei.chong.tan@intel.com> LKML-Reference: <B28277FD4E0F9247A3D55704C440A140D5D683F3@pgsmsx504.gar.corp.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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