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2014-06-11perf: Drop sample rate when sampling is too slowDave Hansen
commit 14c63f17b1fde5a575a28e96547a22b451c71fb5 upstream. This patch keeps track of how long perf's NMI handler is taking, and also calculates how many samples perf can take a second. If the sample length times the expected max number of samples exceeds a configurable threshold, it drops the sample rate. This way, we don't have a runaway sampling process eating up the CPU. This patch can tend to drop the sample rate down to level where perf doesn't work very well. *BUT* the alternative is that my system hangs because it spends all of its time handling NMIs. I'll take a busted performance tool over an entire system that's busted and undebuggable any day. BTW, my suspicion is that there's still an underlying bug here. Using the HPET instead of the TSC is definitely a contributing factor, but I suspect there are some other things going on. But, I can't go dig down on a bug like that with my machine hanging all the time. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@ghostprotocols.net Cc: Dave Hansen <dave@sr71.net> [ Prettified it a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Weng Meiling <wengmeiling.weng@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-06perf/x86: Fix event schedulingPeter Zijlstra
commit 26e61e8939b1fe8729572dabe9a9e97d930dd4f6 upstream. Vince "Super Tester" Weaver reported a new round of syscall fuzzing (Trinity) failures, with perf WARN_ON()s triggering. He also provided traces of the failures. This is I think the relevant bit: > pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_disable: x86_pmu_disable > pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_state: Events: { > pec_1076_warn-2804 [000] d... 147.926156: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null)) > pec_1076_warn-2804 [000] d... 147.926158: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926159: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926160: x86_pmu_state: n_events: 1, n_added: 0, n_txn: 1 > pec_1076_warn-2804 [000] d... 147.926161: x86_pmu_state: Assignment: { > pec_1076_warn-2804 [000] d... 147.926162: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926163: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926166: collect_events: Adding event: 1 (ffff880119ec8800) So we add the insn:p event (fd[23]). At this point we should have: n_events = 2, n_added = 1, n_txn = 1 > pec_1076_warn-2804 [000] d... 147.926170: collect_events: Adding event: 0 (ffff8800c9e01800) > pec_1076_warn-2804 [000] d... 147.926172: collect_events: Adding event: 4 (ffff8800cbab2c00) We try and add the {BP,cycles,br_insn} group (fd[3], fd[4], fd[15]). These events are 0:cycles and 4:br_insn, the BP event isn't x86_pmu so that's not visible. group_sched_in() pmu->start_txn() /* nop - BP pmu */ event_sched_in() event->pmu->add() So here we should end up with: 0: n_events = 3, n_added = 2, n_txn = 2 4: n_events = 4, n_added = 3, n_txn = 3 But seeing the below state on x86_pmu_enable(), the must have failed, because the 0 and 4 events aren't there anymore. Looking at group_sched_in(), since the BP is the leader, its event_sched_in() must have succeeded, for otherwise we would not have seen the sibling adds. But since neither 0 or 4 are in the below state; their event_sched_in() must have failed; but I don't see why, the complete state: 0,0,1:p,4 fits perfectly fine on a core2. However, since we try and schedule 4 it means the 0 event must have succeeded! Therefore the 4 event must have failed, its failure will have put group_sched_in() into the fail path, which will call: event_sched_out() event->pmu->del() on 0 and the BP event. Now x86_pmu_del() will reduce n_events; but it will not reduce n_added; giving what we see below: n_event = 2, n_added = 2, n_txn = 2 > pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_enable: x86_pmu_enable > pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_state: Events: { > pec_1076_warn-2804 [000] d... 147.926179: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null)) > pec_1076_warn-2804 [000] d... 147.926181: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926182: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: n_events: 2, n_added: 2, n_txn: 2 > pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: Assignment: { > pec_1076_warn-2804 [000] d... 147.926186: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: 1->0 tag: 1 config: 1 (ffff880119ec8800) > pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926190: x86_pmu_enable: S0: hwc->idx: 33, hwc->last_cpu: 0, hwc->last_tag: 1 hwc->state: 0 So the problem is that x86_pmu_del(), when called from a group_sched_in() that fails (for whatever reason), and without x86_pmu TXN support (because the leader is !x86_pmu), will corrupt the n_added state. Reported-and-Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Stephane Eranian <eranian@google.com> Cc: Dave Jones <davej@redhat.com> Link: http://lkml.kernel.org/r/20140221150312.GF3104@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-21perf/x86: Check all MSRs before passing hw checkGeorge Dunlap
check_hw_exists() has a number of checks which go to two exit paths: msr_fail and bios_fail. Checks classified as msr_fail will cause check_hw_exists() to return false, causing the PMU not to be used; bios_fail checks will only cause a warning to be printed, but will return true. The problem is that if there are both msr failures and bios failures, and the routine hits a bios_fail check first, it will exit early and return true, not finishing the rest of the msr checks. If those msrs are in fact broken, it will cause them to be used erroneously. In the case of a Xen PV VM, the guest OS has read access to all the MSRs, but write access is white-listed to supported features. Writes to unsupported MSRs have no effect. The PMU MSRs are not (typically) supported, because they are expensive to save and restore on a VM context switch. One of the "msr_fail" checks is supposed to detect this circumstance (ether for Xen or KVM) and disable the harware PMU. However, on one of my AMD boxen, there is (apparently) a broken BIOS which triggers one of the bios_fail checks. In particular, MSR_K7_EVNTSEL0 has the ARCH_PERFMON_EVENTSEL_ENABLE bit set. The guest kernel detects this because it has read access to all MSRs, and causes it to skip the rest of the checks and try to use the non-existent hardware PMU. This minimally causes a lot of useless instruction emulation and Xen console spam; it may cause other issues with the watchdog as well. This changset causes check_hw_exists() to go through all of the msr checks, failing and returning false if any of them fail. This makes sure that a guest running under Xen without a virtual PMU will detect that there is no functioning PMU and not attempt to use it. This problem affects kernels as far back as 3.2, and should thus be considered for backport. Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Link: http://lkml.kernel.org/r/1365000388-32448-1-git-send-email-george.dunlap@eu.citrix.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-01perf/x86: Add memory profiling via PEBS Load LatencyStephane Eranian
This patch adds support for memory profiling using the PEBS Load Latency facility. Load accesses are sampled by HW and the instruction address, data address, load latency, data source, tlb, locked information can be saved in the sampling buffer if using the PERF_SAMPLE_COST (for latency), PERF_SAMPLE_ADDR, PERF_SAMPLE_DATA_SRC types. To enable PEBS Load Latency, users have to use the model specific event: - on NHM/WSM: MEM_INST_RETIRED:LATENCY_ABOVE_THRESHOLD - on SNB/IVB: MEM_TRANS_RETIRED:LATENCY_ABOVE_THRESHOLD To make things easier, this patch also exports a generic alias via sysfs: mem-loads. It export the right event encoding based on the host CPU and can be used directly by the perf tool. Loosely based on Intel's Lin Ming patch posted on LKML in July 2011. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: ak@linux.intel.com Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1359040242-8269-9-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-04-01perf/x86: Add flags to event constraintsStephane Eranian
This patch adds a flags field to each event constraint. It can be used to store event specific features which can then later be used by scheduling code or low-level x86 code. The flags are propagated into event->hw.flags during the get_event_constraint() call. They are cleared during the put_event_constraint() call. This mechanism is going to be used by the PEBS-LL patches. It avoids defining yet another table to hold event specific information. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: ak@linux.intel.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1359040242-8269-4-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-03-26perf/x86: Improve sysfs event mapping with event stringStephane Eranian
This patch extends Jiri's changes to make generic events mapping visible via sysfs. The patch extends the mechanism to non-generic events by allowing the mappings to be hardcoded in strings. This mechanism will be used by the PEBS-LL patch later on. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: ak@linux.intel.com Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1359040242-8269-3-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org> [ fixed up conflict with 2663960 "perf: Make EVENT_ATTR global" ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-03-26perf/x86: Support CPU specific sysfs eventsAndi Kleen
Add a way for the CPU initialization code to register additional events, and merge them into the events attribute directory. Used in the next patch. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1359040242-8269-2-git-send-email-eranian@google.com [ small cleanups ] Signed-off-by: Ingo Molnar <mingo@kernel.org> [ merge_attr returns a **, not just * ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-02-06perf/x86: Allow for architecture specific RDPMC indexesJacob Shin
Similar to config_base and event_base, allow architecture specific RDPMC ECX values. Signed-off-by: Jacob Shin <jacob.shin@amd.com> Acked-by: Stephane Eranian <eranian@google.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360171589-6381-6-git-send-email-jacob.shin@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-01-31perf: Make EVENT_ATTR globalSukadev Bhattiprolu
Rename EVENT_ATTR() to PMU_EVENT_ATTR() and make it global so it is available to all architectures. Further to allow architectures flexibility, have PMU_EVENT_ATTR() pass in the variable name as a parameter. Changelog[v2] - [Jiri Olsa] No need to define PMU_EVENT_PTR() Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Anton Blanchard <anton@au1.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/20130123062422.GC13720@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-10perf x86: revert 20b279 - require exclude_guest to use PEBS - kernel sideDavid Ahern
This patch is brought to you by the letter 'H'. Commit 20b279 breaks compatiblity with older perf binaries when run with precise modifier (:p or :pp) by requiring the exclude_guest attribute to be set. Older binaries default exclude_guest to 0 (ie., wanting guest-based samples) unless host only profiling is requested (:H modifier). The workaround for older binaries is to add H to the modifier list (e.g., -e cycles:ppH - toggles exclude_guest to 1). This was deemed unacceptable by Linus: https://lkml.org/lkml/2012/12/12/570 Between family in town and the fresh snow in Breckenridge there is no time left to be working on the proper fix for this over the holidays. In the New Year I have more pressing problems to resolve -- like some memory leaks in perf which are proving to be elusive -- although the aforementioned snow is probably why they are proving to be elusive. Either way I do not have any spare time to work on this and from the time I have managed to spend on it the solution is more difficult than just moving to a new exclude_guest flag (does not work) or flipping the logic to include_guest (which is not as trivial as one would think). So, two options: silently force exclude_guest on as suggested by Gleb which means no impact to older perf binaries or revert the original patch which caused the breakage. This patch does the latter -- reverts the original patch that introduced the regression. The problem can be revisited in the future as time allows. Signed-off-by: David Ahern <dsahern@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Richter <robert.richter@amd.com> Link: http://lkml.kernel.org/r/1356749767-17322-1-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-10-30perf/x86: Fix sparse warningsPeter Huewe
FYI, there are new sparse warnings: arch/x86/kernel/cpu/perf_event.c:1356:18: sparse: symbol 'events_attr' was not declared. Should it be static? This patch makes it static and also adds the static keyword to fix arch/x86/kernel/cpu/perf_event.c:1344:9: warning: symbol 'events_sysfs_show' was not declared. Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com> Cc: fengguang.wu@intel.com Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/n/tip-lerdpXlnruh0yvWs2owwuizl@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-24perf/x86: Add hardware events translations for AMD cpusJiri Olsa
Add support for AMD processors to display 'events' sysfs directory (/sys/devices/cpu/events/) with hw event translations: # ls /sys/devices/cpu/events/ branch-instructions branch-misses bus-cycles cache-misses cache-references cpu-cycles instructions ref-cycles stalled-cycles-backend stalled-cycles-frontend Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1349873598-12583-5-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-24perf/x86: Add hardware events translations for Intel cpusJiri Olsa
Add support for Intel processors to display 'events' sysfs directory (/sys/devices/cpu/events/) with hw event translations: # ls /sys/devices/cpu/events/ branch-instructions branch-misses bus-cycles cache-misses cache-references cpu-cycles instructions ref-cycles stalled-cycles-backend stalled-cycles-frontend Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1349873598-12583-4-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-24perf/x86: Filter out undefined events from sysfs events attributeJiri Olsa
The sysfs events group attribute currently shows all hw events, including also undefined ones. This patch filters out all undefined events out of the sysfs events group attribute, so they don't even show up. Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1349873598-12583-3-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-24perf/x86: Make hardware event translations available in sysfsJiri Olsa
Add support to display hardware events translations available through the sysfs. Add 'events' group attribute under the sysfs x86 PMU record with attribute/file for each hardware event. This patch adds only backbone for PMUs to display config under 'events' directory. The specific PMU support itself will come in next patches, however this is how the sysfs group will look like: # ls /sys/devices/cpu/events/ branch-instructions branch-misses bus-cycles cache-misses cache-references cpu-cycles instructions ref-cycles stalled-cycles-backend stalled-cycles-frontend The file - hw event ID mapping is: file hw event ID --------------------------------------------------------------- cpu-cycles PERF_COUNT_HW_CPU_CYCLES instructions PERF_COUNT_HW_INSTRUCTIONS cache-references PERF_COUNT_HW_CACHE_REFERENCES cache-misses PERF_COUNT_HW_CACHE_MISSES branch-instructions PERF_COUNT_HW_BRANCH_INSTRUCTIONS branch-misses PERF_COUNT_HW_BRANCH_MISSES bus-cycles PERF_COUNT_HW_BUS_CYCLES stalled-cycles-frontend PERF_COUNT_HW_STALLED_CYCLES_FRONTEND stalled-cycles-backend PERF_COUNT_HW_STALLED_CYCLES_BACKEND ref-cycles PERF_COUNT_HW_REF_CPU_CYCLES Each file in the 'events' directory contains the term translation for the symbolic hw event for the currently running cpu model. # cat /sys/devices/cpu/events/stalled-cycles-backend event=0xb1,umask=0x01,inv,cmask=0x01 Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1349873598-12583-2-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-24x86/perf: Fix virtualization sanity checkAndre Przywara
In check_hw_exists() we try to detect non-emulated MSR accesses by writing an arbitrary value into one of the PMU registers and check if it's value after a readout is still the same. This algorithm silently assumes that the register does not contain the magic value already, which is wrong in at least one situation. Fix the algorithm to really do a read-modify-write cycle. This fixes a warning under Xen under some circumstances on AMD family 10h CPUs. The reasons in more details actually sound like a story from Believe It or Not!: First you need an AMD family 10h/12h CPU. These do not reset the PERF_CTR registers on a reboot. Now you boot bare metal Linux, which goes successfully through this check, but leaves the magic value of 0xabcd in the register. You don't use the performance counters, but do a reboot (warm reset). Then you choose to boot Xen. The check will be triggered with a recent Linux kernel as Dom0 again, trying to write 0xabcd into the MSR. Xen silently drops the write (expected), but the subsequent read will return the value in the register, which just happens to be the expected magic value. Thus the test misleadingly succeeds, leaving the kernel in the belief that the PMU is available. This will trigger the following message: [ 0.020294] ------------[ cut here ]------------ [ 0.020311] WARNING: at arch/x86/xen/enlighten.c:730 xen_apic_write+0x15/0x17() [ 0.020318] Hardware name: empty [ 0.020323] Modules linked in: [ 0.020334] Pid: 1, comm: swapper/0 Not tainted 3.3.8 #7 [ 0.020340] Call Trace: [ 0.020354] [<ffffffff81050379>] warn_slowpath_common+0x80/0x98 [ 0.020369] [<ffffffff810503a6>] warn_slowpath_null+0x15/0x17 [ 0.020378] [<ffffffff810034df>] xen_apic_write+0x15/0x17 [ 0.020392] [<ffffffff8101cb2b>] perf_events_lapic_init+0x2e/0x30 [ 0.020410] [<ffffffff81ee4dd0>] init_hw_perf_events+0x250/0x407 [ 0.020419] [<ffffffff81ee4b80>] ? check_bugs+0x2d/0x2d [ 0.020430] [<ffffffff81002181>] do_one_initcall+0x7a/0x131 [ 0.020444] [<ffffffff81edbbf9>] kernel_init+0x91/0x15d [ 0.020456] [<ffffffff817caaa4>] kernel_thread_helper+0x4/0x10 [ 0.020471] [<ffffffff817c347c>] ? retint_restore_args+0x5/0x6 [ 0.020481] [<ffffffff817caaa0>] ? gs_change+0x13/0x13 [ 0.020500] ---[ end trace a7919e7f17c0a725 ]--- The new code will change every of the 16 low bits read from the register and tries to write and read-back that modified number from the MSR. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Avi Kivity <avi@redhat.com> Link: http://lkml.kernel.org/r/1349797115-28346-2-git-send-email-andre.przywara@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-16perf: Require exclude_guest to use PEBS - kernel side enforcementPeter Zijlstra
Intel PEBS in VT-x context uses the DS address as a guest linear address, even though its programmed by the host as a host linear address. This either results in guest memory corruption and or the hardware faulting and 'crashing' the virtual machine. Therefore we have to disable PEBS on VT-x enter and re-enable on VT-x exit, enforcing a strict exclude_guest. This patch enforces exclude_guest kernel side. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Avi Kivity <avi@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Robert Richter <robert.richter@amd.com> Link: http://lkml.kernel.org/r/1347569955-54626-3-git-send-email-dsahern@gmail.com Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-07-31perf/x86: Fix USER/KERNEL tagging of samples properlyPeter Zijlstra
Some PMUs don't provide a full register set for their sample, specifically 'advanced' PMUs like AMD IBS and Intel PEBS which provide 'better' than regular interrupt accuracy. In this case we use the interrupt regs as basis and over-write some fields (typically IP) with different information. The perf core however uses user_mode() to distinguish user/kernel samples, user_mode() relies on regs->cs. If the interrupt skid pushed us over a boundary the new IP might not be in the same domain as the interrupt. Commit ce5c1fe9a9e ("perf/x86: Fix USER/KERNEL tagging of samples") tried to fix this by making the perf core use kernel_ip(). This however is wrong (TM), as pointed out by Linus, since it doesn't allow for VM86 and non-zero based segments in IA32 mode. Therefore, provide a new helper to set the regs->ip field, set_linear_ip(), which massages the regs into a suitable state assuming the provided IP is in fact a linear address. Also modify perf_instruction_pointer() and perf_callchain_user() to deal with segments base offsets. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1341910954.3462.102.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05perf/x86: Add a microcode revision check for SNB-PEBSPeter Zijlstra
Recent Intel microcode resolved the SNB-PEBS issues, so conditionally enable PEBS on SNB hardware depending on the microcode revision. Thanks to Stephane for figuring out the various microcode revisions. Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-v3672ziwh9damwqwh1uz3krm@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05perf/x86: Improve debug output in check_hw_exists()Robert Richter
It might be of interest which perfctr msr failed. Signed-off-by: Robert Richter <robert.richter@amd.com> [ added hunk to avoid GCC warn ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1340217996-2254-5-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05perf/x86: Move Intel specific code to intel_pmu_init()Robert Richter
There is some Intel specific code in the generic x86 path. Move it to intel_pmu_init(). Since p4 and p6 pmus don't have fixed counters we may skip the check in case such a pmu is detected. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1340217996-2254-3-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05perf/x86: Rename Intel specific macrosRobert Richter
There are macros that are Intel specific and not x86 generic. Rename them into INTEL_*. This patch removes X86_PMC_IDX_GENERIC and does: $ sed -i -e 's/X86_PMC_MAX_/INTEL_PMC_MAX_/g' \ arch/x86/include/asm/kvm_host.h \ arch/x86/include/asm/perf_event.h \ arch/x86/kernel/cpu/perf_event.c \ arch/x86/kernel/cpu/perf_event_p4.c \ arch/x86/kvm/pmu.c $ sed -i -e 's/X86_PMC_IDX_FIXED/INTEL_PMC_IDX_FIXED/g' \ arch/x86/include/asm/perf_event.h \ arch/x86/kernel/cpu/perf_event.c \ arch/x86/kernel/cpu/perf_event_intel.c \ arch/x86/kernel/cpu/perf_event_intel_ds.c \ arch/x86/kvm/pmu.c $ sed -i -e 's/X86_PMC_MSK_/INTEL_PMC_MSK_/g' \ arch/x86/include/asm/perf_event.h \ arch/x86/kernel/cpu/perf_event.c Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1340217996-2254-2-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05Merge branch 'x86/cpu' into perf/coreIngo Molnar
Merge this branch because we changed the wrmsr*_safe() API and there's a conflict. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05Merge branch 'perf/urgent' into perf/coreIngo Molnar
Merge this branch to pick up a fixlet and to update to a more recent base. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05perf/x86: Fix USER/KERNEL tagging of samplesPeter Zijlstra
Several perf interrupt handlers (PEBS,IBS,BTS) re-write regs->ip but do not update the segment registers. So use an regs->ip based test instead of an regs->cs/regs->flags based test. Reported-and-tested-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/n/tip-xxrt0a1zronm1sm36obwc2vy@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-18perf: Export perf_assign_events()Yan, Zheng
Export perf_assign_events() so the uncore code can use it to schedule events. Signed-off-by: Zheng Yan <zheng.z.yan@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1339741902-8449-2-git-send-email-zheng.z.yan@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-18perf/x86/amd: Fix RDPMC index calculation for AMD family 15hRobert Richter
The RDPMC index calculation is wrong for AMD family 15h (X86_FEATURE_ PERFCTR_CORE set). This leads to a #GP when accessing the counter: Pid: 2237, comm: syslog-ng Not tainted 3.5.0-rc1-perf-x86_64-standard-g130ff90 #135 AMD Pike/Pike RIP: 0010:[<ffffffff8100dc33>] [<ffffffff8100dc33>] x86_perf_event_update+0x27/0x66 While the msr address offset is (index << 1) we must use index to select the correct rdpmc. Signed-off-by: Robert Richter <robert.richter@amd.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Vince Weaver <vweaver1@eecs.utk.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-11perf/x86: Convert obsolete simple_strtoul() usage to kstrtoul()Shuah Khan
Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1339384421.3025.8.camel@lorien2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-07x86, cpu: Rename checking_wrmsrl() to wrmsrl_safe()H. Peter Anvin
Rename checking_wrmsrl() to wrmsrl_safe(), to match the naming convention used by all the other MSR access functions/macros. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-06-06perf/x86: Use rdpmc() rather than rdmsr() when possible in the kernelVince Weaver
The rdpmc instruction is faster than the equivelant rdmsr call, so use it when possible in the kernel. The perfctr kernel patches did this, after extensive testing showed rdpmc to always be faster (One can look in etc/costs in the perfctr-2.6 package to see a historical list of the overhead). I have done some tests on a 3.2 kernel, the kernel module I used was included in the first posting of this patch: rdmsr rdpmc Core2 T9900: 203.9 cycles 30.9 cycles AMD fam0fh: 56.2 cycles 9.8 cycles Atom 6/28/2: 129.7 cycles 50.6 cycles The speedup of using rdpmc is large. [ It's probably possible (and desirable) to do this without requiring a new field in the hw_perf_event structure, but the fixed events make this tricky. ] Signed-off-by: Vince Weaver <vweaver1@eecs.utk.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1203011724030.26934@cl320.eecs.utk.edu Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06perf/x86: Fix wrmsrl() debug wrapperPeter Zijlstra
Move the wrmslr() debug wrapper to the common header now that all the include games are gone. Also clean it up a bit to avoid multiple evaluation of the argument. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-l4gkfnivwv4yi5mqxjlovymx@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06perf/x86: Check if user fp is validArun Sharma
Signed-off-by: Arun Sharma <asharma@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1334961696-19580-4-git-send-email-asharma@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06perf/x86: Allow multiple stacksArun Sharma
Without this patch, applications with two different stack regions (eg: native stack vs JIT stack) get truncated callchains even when RBP chaining is present. GDB shows proper stack traces and the frame pointer chaining is intact. This patch disables the (fp < RSP) check, hoping that other checks in the code save the day for us. In our limited testing, this didn't seem to break anything. In the long term, we could potentially have userspace advise the kernel on the range of valid stack addresses, so we don't spend a lot of time unwinding from bogus addresses. Signed-off-by: Arun Sharma <asharma@fb.com> CC: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: linux-perf-users@vger.kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1334961696-19580-2-git-send-email-asharma@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06perf/x86: Fix Intel shared extra MSR allocationPeter Zijlstra
Zheng Yan reported that event group validation can wreck event state when Intel extra_reg allocation changes event state. Validation shouldn't change any persistent state. Cloning events in validate_{event,group}() isn't really pretty either, so add a few special cases to avoid modifying the event state. The code is restructured to minimize the special case impact. Reported-by: Zheng Yan <zheng.z.yan@linux.intel.com> Acked-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1338903031.28282.175.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-09perf: Pass last sampling period to perf_sample_data_init()Robert Richter
We always need to pass the last sample period to perf_sample_data_init(), otherwise the event distribution will be wrong. Thus, modifiyng the function interface with the required period as argument. So basically a pattern like this: perf_sample_data_init(&data, ~0ULL); data.period = event->hw.last_period; will now be like that: perf_sample_data_init(&data, ~0ULL, event->hw.last_period); Avoids unininitialized data.period and simplifies code. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1333390758-10893-3-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-04-26perf: Trivial cleanup of duplicate codeRobert Richter
Removing duplicate code. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1333643084-26776-2-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-31Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates and fixes from Ingo Molnar: "It's mostly fixes, but there's also two late items: - preliminary GTK GUI support for perf report - PMU raw event format descriptors in sysfs, to be parsed by tooling The raw event format in sysfs is a new ABI. For example for the 'CPU' PMU we have: aldebaran:~> ll /sys/bus/event_source/devices/cpu/format/* -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/any -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/cmask -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/edge -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/event -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/inv -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/offcore_rsp -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/pc -r--r--r--. 1 root root 4096 Mar 31 10:29 /sys/bus/event_source/devices/cpu/format/umask those lists of fields contain a specific format: aldebaran:~> cat /sys/bus/event_source/devices/cpu/format/offcore_rsp config1:0-63 So, those who wish to specify raw events can now use the following event format: -e cpu/cmask=1,event=2,umask=3 Most people will not want to specify any events (let alone raw events), they'll just use whatever default event the tools use. But for more obscure PMU events that have no cross-architecture generic events the above syntax is more usable and a bit more structured than specifying hex numbers." * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) perf tools: Remove auto-generated bison/flex files perf annotate: Fix off by one symbol hist size allocation and hit accounting perf tools: Add missing ref-cycles event back to event parser perf annotate: addr2line wants addresses in same format as objdump perf probe: Finder fails to resolve function name to address tracing: Fix ent_size in trace output perf symbols: Handle NULL dso in dso__name_len perf symbols: Do not include libgen.h perf tools: Fix bug in raw sample parsing perf tools: Fix display of first level of callchains perf tools: Switch module.h into export.h perf: Move mmap page data_head offset assertion out of header perf: Fix mmap_page capabilities and docs perf diff: Fix to work with new hists design perf tools: Fix modifier to be applied on correct events perf tools: Fix various casting issues for 32 bits perf tools: Simplify event_read_id exit path tracing: Fix ftrace stack trace entries tracing: Move the tracing_on/off() declarations into CONFIG_TRACING perf report: Add a simple GTK2-based 'perf report' browser ...
2012-03-29Merge branch 'x86-x32-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x32 support for x86-64 from Ingo Molnar: "This tree introduces the X32 binary format and execution mode for x86: 32-bit data space binaries using 64-bit instructions and 64-bit kernel syscalls. This allows applications whose working set fits into a 32 bits address space to make use of 64-bit instructions while using a 32-bit address space with shorter pointers, more compressed data structures, etc." Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c} * 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) x32: Fix alignment fail in struct compat_siginfo x32: Fix stupid ia32/x32 inversion in the siginfo format x32: Add ptrace for x32 x32: Switch to a 64-bit clock_t x32: Provide separate is_ia32_task() and is_x32_task() predicates x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls x86/x32: Fix the binutils auto-detect x32: Warn and disable rather than error if binutils too old x32: Only clear TIF_X32 flag once x32: Make sure TS_COMPAT is cleared for x32 tasks fs: Remove missed ->fds_bits from cessation use of fd_set structs internally fs: Fix close_on_exec pointer in alloc_fdtable x32: Drop non-__vdso weak symbols from the x32 VDSO x32: Fix coding style violations in the x32 VDSO code x32: Add x32 VDSO support x32: Allow x32 to be configured x32: If configured, add x32 system calls to system call tables x32: Handle process creation x32: Signal-related system calls x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h> ...
2012-03-26Merge branch 'linus' into perf/urgentIngo Molnar
Merge reason: we need to fix a non-trivial merge conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-23bitops: rename for_each_set_bit_cont() in favor of analogous list.h functionAkinobu Mita
This renames for_each_set_bit_cont() to for_each_set_bit_from() because it is analogous to list_for_each_entry_from() in list.h rather than list_for_each_entry_continue(). This doesn't remove for_each_set_bit_cont() for now. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23perf: Fix mmap_page capabilities and docsPeter Zijlstra
Complete the syscall-less self-profiling feature and address all complaints, namely: - capabilities, so we can detect what is actually available at runtime Add a capabilities field to perf_event_mmap_page to indicate what is actually available for use. - on x86: RDPMC weirdness due to being 40/48 bits and not sign-extending properly. - ABI documentation as to how all this stuff works. Also improve the documentation for the new features. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vweaver1@eecs.utk.edu> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1332433596.2487.33.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-16perf: Adding sysfs group format attribute for pmu deviceJiri Olsa
Adding sysfs group 'format' attribute for pmu device that contains a syntax description on how to construct raw events. The event configuration is described in following struct pefr_event_attr attributes: config config1 config2 Each sysfs attribute within the format attribute group, describes mapping of name and bitfield definition within one of above attributes. eg: "/sys/...<dev>/format/event" contains "config:0-7" "/sys/...<dev>/format/umask" contains "config:8-15" "/sys/...<dev>/format/usr" contains "config:16" the attribute value syntax is: line: config ':' bits config: 'config' | 'config1' | 'config2" bits: bits ',' bit_term | bit_term bit_term: VALUE '-' VALUE | VALUE Adding format attribute definitions for x86 cpu pmus. Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/n/tip-vhdk5y2hyype9j63prymty36@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-03-05perf: Add callback to flush branch_stack on context switchStephane Eranian
With branch stack sampling, it is possible to filter by priv levels. In system-wide mode, that means it is possible to capture only user level branches. The builtin SW LBR filter needs to disassemble code based on LBR captured addresses. For that, it needs to know the task the addresses are associated with. Because of context switches, the content of the branch stack buffer may contain addresses from different tasks. We need a callback on context switch to either flush the branch stack or save it. This patch adds a new callback in struct pmu which is called during context switches. The callback is called only when necessary. That is when a system-wide context has, at least, one event which uses PERF_SAMPLE_BRANCH_STACK. The callback is never called for per-thread context. In this version, the Intel x86 code simply flushes (resets) the LBR on context switches (fills it with zeroes). Those zeroed branches are then filtered out by the SW filter. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1328826068-11713-11-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-05perf/x86: Sync branch stack sampling with precise_samplingStephane Eranian
If precise sampling is enabled on Intel x86 then perf_event uses PEBS. To correct for the off-by-one error of PEBS, perf_event uses LBR when precise_sample > 1. On Intel x86 PERF_SAMPLE_BRANCH_STACK is implemented using LBR, therefore both features must be coordinated as they may not configure LBR the same way. For PEBS, LBR needs to capture all branches at the priv level of the associated event. This patch checks that the branch type and priv level of BRANCH_STACK is compatible with that of the PEBS LBR requirement, thereby allowing: $ perf record -b any,u -e instructions:upp .... But: $ perf record -b any_call,u -e instructions:upp Is not possible. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1328826068-11713-5-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-05perf/x86: Add Intel LBR sharing logicStephane Eranian
The Intel LBR on some recent processor is capable of filtering branches by type. The filter is configurable via the LBR_SELECT MSR register. There are limitation on how this register can be used. On Nehalem/Westmere, the LBR_SELECT is shared by the two HT threads when HT is on. It is private to each core when HT is off. On SandyBridge, the LBR_SELECT register is private to each thread when HT is on. It is private to each core when HT is off. The kernel must manage the sharing of LBR_SELECT. It allows multiple users on the same logical CPU to use LBR_SELECT as long as they program it with the same value. Across sibling CPUs (HT threads), the same restriction applies on NHM/WSM. This patch implements this sharing logic by leveraging the mechanism put in place for managing the offcore_response shared MSR. We modify __intel_shared_reg_get_constraints() to cause x86_get_event_constraint() to be called because LBR may be associated with events that may be counter constrained. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1328826068-11713-4-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-05Merge branch 'perf/urgent' into perf/coreIngo Molnar
Conflicts: tools/perf/builtin-record.c tools/perf/builtin-top.c tools/perf/perf.h tools/perf/util/top.h Merge reason: resolve these cherry-picking conflicts. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-20x32: Handle process creationH. Peter Anvin
Allow an x32 process to be started. Originally-by: H. J. Lu <hjl.tools@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
2012-02-06Merge branch 'perf/urgent' into perf/coreArnaldo Carvalho de Melo
So that we can get the perf bench exec stack fixes and then apply the remaining fix for the files added after what is in perf/urgent. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-02-03perf: Remove deprecated WARN_ON_ONCE()Stephane Eranian
With the new throttling/unthrottling code introduced with commit: e050e3f0a71b ("perf: Fix broken interrupt rate throttling") we occasionally hit two WARN_ON_ONCE() checks in: - intel_pmu_pebs_enable() - intel_pmu_lbr_enable() - x86_pmu_start() The assertions are no longer problematic. There is a valid path where they can trigger but it is harmless. The assertion can be triggered with: $ perf record -e instructions:pp .... Leading to paths: intel_pmu_pebs_enable intel_pmu_enable_event x86_perf_event_set_period x86_pmu_start perf_adjust_freq_unthr_context perf_event_task_tick scheduler_tick And: intel_pmu_lbr_enable intel_pmu_enable_event x86_perf_event_set_period x86_pmu_start perf_adjust_freq_unthr_context. perf_event_task_tick scheduler_tick cpuc->enabled is always on because when we get to perf_adjust_freq_unthr_context() the PMU is not totally disabled. Furthermore when we need to adjust a period, we only stop the event we need to change and not the entire PMU. Thus, when we re-enable, cpuc->enabled is already set. Note that when we stop the event, both pebs and lbr are stopped if necessary (and possible). Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/20120202110401.GA30911@quad Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21perf: Extend the mmap control page with time (TSC) fieldsPeter Zijlstra
Extend the mmap control page with fields so that userspace can compute time deltas relative to the provided time fields. Currently only implemented for x86 with constant and nonstop TSC. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Arun Sharma <asharma@fb.com> Link: http://lkml.kernel.org/n/tip-3u1jucza77j3wuvs0x2bic0f@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>