- 05 9月, 2015 1 次提交
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由 Guenter Roeck 提交于
The kernel's NMI watchdog has nothing to do with the watchdog subsystem. Its header declarations should be in linux/nmi.h, not linux/watchdog.h. The code provided two sets of dummy functions if HARDLOCKUP_DETECTOR is not configured, one in the include file and one in kernel/watchdog.c. Remove the dummy functions from kernel/watchdog.c and use those from the include file. Signed-off-by: NGuenter Roeck <linux@roeck-us.net> Cc: Stephane Eranian <eranian@google.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Don Zickus <dzickus@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 8月, 2015 1 次提交
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由 Peter Zijlstra 提交于
We fail to free the shared_regs allocation if the constraint_list allocation fails. Cure this and be more consistent in NULL-ing the pointers after free. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 04 8月, 2015 6 次提交
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由 Andi Kleen 提交于
The next patch adds a new perf extra register where 0x1ff is not a valid value. Use 0x11 instead. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1435707205-6676-3-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
Add perf core PMU support for future Intel Skylake CPU cores. The code is based on Haswell/Broadwell. There is a new cache event list, based on the updated Haswell event list. Skylake has removed most counter constraints on basic events, so the basic constraints table now only has a single entry (plus the fixed counters). TSX support and various other setups are all shared with Haswell. Skylake has 32 LBR entries. Add a new LBR init function to set this up. The filters are all the same as Haswell. It also has a new LBR format with a separate LBR_INFO_* MSR, but that has been already added earlier. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1431285767-27027-7-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
With Arch Perfmon v4 the PMU ack unfreezes the LBRs. So we need to do the PMU ack after the LBR reading, otherwise the LBRs would be polluted by the PMI handler. This is a minimal change. In principle the ACK could be moved much later. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1431285767-27027-10-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
ArchPerfmon v4 has some new status bits in GLOBAL_STATUS. These need to be ignored when deciding whether a NMI was an NMI, to avoid eating all NMIs when they stay set, see: b292d7a1 ("perf/x86/intel: ignore CondChgd bit to avoid false NMI handling") This patch ignores the new ASIF bit, which indicates that SGX interfered with the PMU, and also the new LBR freezing bits, which are set when the LBRs get frozen, plus the existing CondChange (set by JTAG debuggers and some buggy BIOSes) Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1431285767-27027-8-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
With PEBSv3 the PEBS record contains a time stamp. That means we can allow free-running PEBS without a PMI even if the user program requested a time stamp. This avoids the need to use -T to get free running PEBS, and also avoids any problems with mis-identifying MMAPs later. Move the free_running_flags state into a variable in x86_pmu and use it. This only works when no explicit clock_id is set. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: eranian@google.com Cc: jolsa@redhat.com Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1432786398-23861-2-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Kan Liang 提交于
AVG_LATENCY(bit 38) is only available on MSR_OFFCORE_RSP0. So the bit should be removed from RSP1 valid_mask. Since RSP0 and RSP1 may have different valid_mask, intel_alt_er should validate the config on the alternate offcore reg before replacing it. Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1435170215-5017-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 19 6月, 2015 2 次提交
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由 Palik, Imre 提交于
Architectural performance monitoring, version 1, doesn't support fixed counters. Currently, even if a hypervisor advertises support for architectural performance monitoring version 1, perf may still try to use the fixed counters, as the constraints are set up based on the CPU model. This patch ensures that perf honors the architectural performance monitoring version returned by CPUID, and it only uses the fixed counters for version 2 and above. (Some of the ideas in this patch came from Peter Zijlstra.) Signed-off-by: NImre Palik <imrep@amazon.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Anthony Liguori <aliguori@amazon.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1433767609-1039-1-git-send-email-imrep.amz@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
This patch adds additional model numbers for Broadwell to perf. Support for Broadwell with Iris Pro (Intel Core i7-57xxC) and support for Broadwell Server Xeon. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1434055942-28253-1-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 07 6月, 2015 3 次提交
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由 Yan, Zheng 提交于
Flush the PEBS buffer during context switches if PEBS interrupt threshold is larger than one. This allows perf to supply TID for sample outputs. Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com> Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: eranian@google.com Link: http://lkml.kernel.org/r/1430940834-8964-6-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Yan, Zheng 提交于
PEBS always had the capability to log samples to its buffers without an interrupt. Traditionally perf has not used this but always set the PEBS threshold to one. For frequently occurring events (like cycles or branches or load/store) this in term requires using a relatively high sampling period to avoid overloading the system, by only processing PMIs. This in term increases sampling error. For the common cases we still need to use the PMI because the PEBS hardware has various limitations. The biggest one is that it can not supply a callgraph. It also requires setting a fixed period, as the hardware does not support adaptive period. Another issue is that it cannot supply a time stamp and some other options. To supply a TID it requires flushing on context switch. It can however supply the IP, the load/store address, TSX information, registers, and some other things. So we can make PEBS work for some specific cases, basically as long as you can do without a callgraph and can set the period you can use this new PEBS mode. The main benefit is the ability to support much lower sampling period (down to -c 1000) without extensive overhead. One use cases is for example to increase the resolution of the c2c tool. Another is double checking when you suspect the standard sampling has too much sampling error. Some numbers on the overhead, using cycle soak, comparing the elapsed time from "kernbench -M -H" between plain (threshold set to one) and multi (large threshold). The test command for plain: "perf record --time -e cycles:p -c $period -- kernbench -M -H" The test command for multi: "perf record --no-time -e cycles:p -c $period -- kernbench -M -H" ( The only difference of test command between multi and plain is time stamp options. Since time stamp is not supported by large PEBS threshold, it can be used as a flag to indicate if large threshold is enabled during the test. ) period plain(Sec) multi(Sec) Delta 10003 32.7 16.5 16.2 20003 30.2 16.2 14.0 40003 18.6 14.1 4.5 80003 16.8 14.6 2.2 100003 16.9 14.1 2.8 800003 15.4 15.7 -0.3 1000003 15.3 15.2 0.2 2000003 15.3 15.1 0.1 With periods below 100003, plain (threshold one) cause much more overhead. With 10003 sampling period, the Elapsed Time for multi is even 2X faster than plain. Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com> Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: eranian@google.com Link: http://lkml.kernel.org/r/1430940834-8964-5-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Yan, Zheng 提交于
When a fixed period is specified, this patch makes perf use the PEBS auto reload mechanism. This makes normal profiling faster, because it avoids one costly MSR write in the PMI handler. However, the reset value will be loaded by hardware assist. There is a small delay compared to the previous non-auto-reload mechanism. The delay time is arbitrary, but very small. The assist cost is 400-800 cycles, assuming common cases with everything cached. The minimum period the patch currently uses is 10000. In that extreme case it can be ~10% if cycles are used. Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com> Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: eranian@google.com Link: http://lkml.kernel.org/r/1430940834-8964-2-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 27 5月, 2015 11 次提交
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由 Bartosz Golaszewski 提交于
Rename topology_thread_cpumask() to topology_sibling_cpumask() for more consistency with scheduler code. Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk> Acked-by: NCatalin Marinas <catalin.marinas@arm.com> Cc: Benoit Cousson <bcousson@baylibre.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jean Delvare <jdelvare@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/1432645896-12588-2-git-send-email-bgolaszewski@baylibre.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Don't bother with taking locks if we're not actually going to do anything. Also, drop the _irqsave(), this is very much only called from IRQ-disabled context. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
For some obscure reason intel_{start,stop}_scheduling() copy the HT state to an intermediate array. This would make sense if we ever were to make changes to it which we'd have to discard. Except we don't. By the time we call intel_commit_scheduling() we're; as the name implies; committed to them. We'll never back out. A further hint its pointless is that stop_scheduling() unconditionally publishes the state. So the intermediate array is pointless, modify the state in place and kill the extra array. And remove the pointless array initialization: INTEL_EXCL_UNUSED == 0. Note; all is serialized by intel_excl_cntr::lock. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Both intel_commit_scheduling() and intel_get_excl_contraints() test for cntr < 0. The only way that can happen (aside from a bug) is through validate_event(), however that is already captured by the cpuc->is_fake test. So remove these test and simplify the code. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Move the code of intel_commit_scheduling() to the right place, which is in between start() and stop(). No change in functionality. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
The intel_commit_scheduling() callback is pointlessly different from the start and stop scheduling callback. Furthermore, the constraint should never be NULL, so remove that test. Even though we'll never get called (because we NULL the callbacks) when !is_ht_workaround_enabled() put that test in. Collapse the (pointless) WARN_ON_ONCE() and bail on !cpuc->excl_cntrs -- this is doubly pointless, because its the same condition as is_ht_workaround_enabled() which was already pointless because the whole method won't ever be called. Furthremore, make all the !excl_cntrs test WARN_ON_ONCE(); they're all pointless, because the above, either the function ({get,put}_excl_constraint) are already predicated on it existing or the is_ht_workaround_enabled() thing is the same test. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
We have two 'struct event_constraint' local variables in intel_get_excl_constraints(): 'cx' and 'c'. Instead of using 'cx' after the dynamic allocation, put all 'cx' inside the dynamic allocation block and use 'c' outside of it. Also use direct assignment to copy the structure; let the compiler figure it out. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Lockdep is very good at finding incorrect IRQ state while locking and is far better at telling us if we hold a lock than the _is_locked() API. It also generates less code for !DEBUG kernels. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
For some obscure reason the current code accounts the current SMT thread's state on the remote thread and reads the remote's state on the local SMT thread. While internally consistent, and 'correct' its pointless confusion we can do without. Flip them the right way around. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
The (SNB/IVB/HSW) HT bug only affects events that can be programmed onto GP counters, therefore we should only limit the number of GP counters that can be used per cpu -- iow we should not constrain the FP counters. Furthermore, we should only enfore such a limit when there are in fact exclusive events being scheduled on either sibling. Reported-by: NVince Weaver <vincent.weaver@maine.edu> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> [ Fixed build fail for the !CONFIG_CPU_SUP_INTEL case. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Commit 43b45780 ("perf/x86: Reduce stack usage of x86_schedule_events()") violated the rule that 'fake' scheduling; as used for event/group validation; should not change the event state. This went mostly un-noticed because repeated calls of x86_pmu::get_event_constraints() would give the same result. And x86_pmu::put_event_constraints() would mostly not do anything. Commit e979121b ("perf/x86/intel: Implement cross-HT corruption bug workaround") made the situation much worse by actually setting the event->hw.constraint value to NULL, so when validation and actual scheduling interact we get NULL ptr derefs. Fix it by removing the constraint pointer from the event and move it back to an array, this time in cpuc instead of on the stack. validate_group() x86_schedule_events() event->hw.constraint = c; # store <context switch> perf_task_event_sched_in() ... x86_schedule_events(); event->hw.constraint = c2; # store ... put_event_constraints(event); # assume failure to schedule intel_put_event_constraints() event->hw.constraint = NULL; <context switch end> c = event->hw.constraint; # read -> NULL if (!test_bit(hwc->idx, c->idxmsk)) # <- *BOOM* NULL deref This in particular is possible when the event in question is a cpu-wide event and group-leader, where the validate_group() tries to add an event to the group. Reported-by: NVince Weaver <vincent.weaver@maine.edu> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Hunter <ahh@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 43b45780 ("perf/x86: Reduce stack usage of x86_schedule_events()") Fixes: e979121b ("perf/x86/intel: Implement cross-HT corruption bug workaround") Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 08 5月, 2015 1 次提交
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由 Kan Liang 提交于
iTLB-load-misses and LLC-load-misses count incorrectly on SLM. There is no ITLB.MISSES support on SLM. Event PAGE_WALKS.I_SIDE_WALK should be used to count iTLB-load-misses. This event counts when an instruction (I) page walk is completed or started. Since a page walk implies a TLB miss, the number of TLB misses can be counted by counting the number of pagewalks. DMND_DATA_RD counts both demand and DCU prefetch data reads. However, LLC-load-misses should only count demand reads. There is no way to not include prefetches with a single counter on SLM. So the LLC-load-misses support should be removed on SLM. Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1429608881-5055-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 22 4月, 2015 1 次提交
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由 Jiri Olsa 提交于
The core_pmu does not define cpu_* callbacks, which handles allocation of 'struct cpu_hw_events::shared_regs' data, initialization of debug store and PMU_FL_EXCL_CNTRS counters. While this probably won't happen on bare metal, virtual CPU can define x86_pmu.extra_regs together with PMU version 1 and thus be using core_pmu -> using shared_regs data without it being allocated. That could could leave to following panic: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8152cd4f>] _spin_lock_irqsave+0x1f/0x40 SNIP [<ffffffff81024bd9>] __intel_shared_reg_get_constraints+0x69/0x1e0 [<ffffffff81024deb>] intel_get_event_constraints+0x9b/0x180 [<ffffffff8101e815>] x86_schedule_events+0x75/0x1d0 [<ffffffff810586dc>] ? check_preempt_curr+0x7c/0x90 [<ffffffff810649fe>] ? try_to_wake_up+0x24e/0x3e0 [<ffffffff81064ba2>] ? default_wake_function+0x12/0x20 [<ffffffff8109eb16>] ? autoremove_wake_function+0x16/0x40 [<ffffffff810577e9>] ? __wake_up_common+0x59/0x90 [<ffffffff811a9517>] ? __d_lookup+0xa7/0x150 [<ffffffff8119db5f>] ? do_lookup+0x9f/0x230 [<ffffffff811a993a>] ? dput+0x9a/0x150 [<ffffffff8119c8f5>] ? path_to_nameidata+0x25/0x60 [<ffffffff8119e90a>] ? __link_path_walk+0x7da/0x1000 [<ffffffff8101d8f9>] ? x86_pmu_add+0xb9/0x170 [<ffffffff8101d7a7>] x86_pmu_commit_txn+0x67/0xc0 [<ffffffff811b07b0>] ? mntput_no_expire+0x30/0x110 [<ffffffff8119c731>] ? path_put+0x31/0x40 [<ffffffff8107c297>] ? current_fs_time+0x27/0x30 [<ffffffff8117d170>] ? mem_cgroup_get_reclaim_stat_from_page+0x20/0x70 [<ffffffff8111b7aa>] group_sched_in+0x13a/0x170 [<ffffffff81014a29>] ? sched_clock+0x9/0x10 [<ffffffff8111bac8>] ctx_sched_in+0x2e8/0x330 [<ffffffff8111bb7b>] perf_event_sched_in+0x6b/0xb0 [<ffffffff8111bc36>] perf_event_context_sched_in+0x76/0xc0 [<ffffffff8111eb3b>] perf_event_comm+0x1bb/0x2e0 [<ffffffff81195ee9>] set_task_comm+0x69/0x80 [<ffffffff81195fe1>] setup_new_exec+0xe1/0x2e0 [<ffffffff811ea68e>] load_elf_binary+0x3ce/0x1ab0 Adding cpu_(prepare|starting|dying) for core_pmu to have shared_regs data allocated for core_pmu. AFAICS there's no harm to initialize debug store and PMU_FL_EXCL_CNTRS either for core_pmu. Signed-off-by: NJiri Olsa <jolsa@kernel.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/20150421152623.GC13169@krava.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 17 4月, 2015 1 次提交
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由 Kan Liang 提交于
Same as Haswell, Broadwell also support the LBR callstack. Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NAndi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1427962377-40955-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 02 4月, 2015 13 次提交
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由 Andi Kleen 提交于
The perf PMI currently does unnecessary MSR accesses when LBRs are enabled. We use LBR freezing, or when in callstack mode force the LBRs to only filter on ring 3. So there is no need to disable the LBRs explicitely in the PMI handler. Also we always unnecessarily rewrite LBR_SELECT in the LBR handler, even though it can never change. 5) | /* write_msr: MSR_LBR_SELECT(1c8), value 0 */ 5) | /* read_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ 5) | /* write_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ 5) | /* write_msr: MSR_CORE_PERF_GLOBAL_CTRL(38f), value 70000000f */ 5) | /* write_msr: MSR_CORE_PERF_GLOBAL_CTRL(38f), value 0 */ 5) | /* write_msr: MSR_LBR_SELECT(1c8), value 0 */ 5) | /* read_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ 5) | /* write_msr: MSR_IA32_DEBUGCTLMSR(1d9), value 1801 */ This patch: - Avoids disabling already frozen LBRs unnecessarily in the PMI - Avoids changing LBR_SELECT in the PMI Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1426871484-21285-1-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
The PMU reset code didn't quite keep up with newer PMU features. Improve it a bit to really reset a modern PMU: - Clear all overflow status - Clear LBRs and freezing state - Disable fixed counters too Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1425059312-18217-2-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Stephane Eranian 提交于
This patch disables the PMU HT bug when Hyperthreading (HT) is disabled. We cannot do this test immediately when perf_events is initialized. We need to wait until the topology information is setup properly. As such, we register a later initcall, check the topology and potentially disable the workaround. To do this, we need to ensure there is no user of the PMU. At this point of the boot, the only user is the NMI watchdog, thus we disable it during the switch and re-enable it right after. Having the workaround disabled when it is not needed provides some benefits by limiting the overhead is time and space. The workaround still ensures correct scheduling of the corrupting memory events (0xd0, 0xd1, 0xd2) when HT is off. Those events can only be measured on counters 0-3. Something else the current kernel did not handle correctly. Signed-off-by: NStephane Eranian <eranian@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Cc: maria.n.dimakopoulou@gmail.com Link: http://lkml.kernel.org/r/1416251225-17721-13-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Stephane Eranian 提交于
perf/x86/intel: Limit to half counters when the HT workaround is enabled, to avoid exclusive mode starvation This patch limits the number of counters available to each CPU when the HT bug workaround is enabled. This is necessary to avoid situation of counter starvation. Such can arise from configuration where one HT thread, HT0, is using all 4 counters with corrupting events which require exclusion the the sibling HT, HT1. In such case, HT1 would not be able to schedule any event until HT0 is done. To mitigate this problem, this patch artificially limits the number of counters to 2. That way, we can gurantee that at least 2 counters are not in exclusive mode and therefore allow the sibling thread to schedule events of the same type (system vs. per-thread). The 2 counters are not determined in advance. We simply set the limit to two events per HT. This helps mitigate starvation in case of events with specific counter constraints such a PREC_DIST. Note that this does not elimintate the starvation is all cases. But it is better than not having it. (Solution suggested by Peter Zjilstra.) Signed-off-by: NStephane Eranian <eranian@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Cc: maria.n.dimakopoulou@gmail.com Link: http://lkml.kernel.org/r/1416251225-17721-11-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Stephane Eranian 提交于
With dynamic constraint, we need to restart from the static constraints each time the intel_get_event_constraints() is called. Signed-off-by: NStephane Eranian <eranian@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1416251225-17721-10-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Maria Dimakopoulou 提交于
This patches activates the HT bug workaround for the SNB/IVB/HSW processors. This covers non-PEBS mode. Activation is done thru the constraint tables. Both client and server processors needs this workaround. Signed-off-by: NMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NStephane Eranian <eranian@google.com> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1416251225-17721-8-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Maria Dimakopoulou 提交于
This patch implements a software workaround for a HW erratum on Intel SandyBridge, IvyBridge and Haswell processors with Hyperthreading enabled. The errata are documented for each processor in their respective specification update documents: - SandyBridge: BJ122 - IvyBridge: BV98 - Haswell: HSD29 The bug causes silent counter corruption across hyperthreads only when measuring certain memory events (0xd0, 0xd1, 0xd2, 0xd3). Counters measuring those events may leak counts to the sibling counter. For instance, counter 0, thread 0 measuring event 0xd0, may leak to counter 0, thread 1, regardless of the event measured there. The size of the leak is not predictible. It all depends on the workload and the state of each sibling hyper-thread. The corrupting events do undercount as a consequence of the leak. The leak is compensated automatically only when the sibling counter measures the exact same corrupting event AND the workload is on the two threads is the same. Given, there is no way to guarantee this, a work-around is necessary. Furthermore, there is a serious problem if the leaked count is added to a low-occurrence event. In that case the corruption on the low occurrence event can be very large, e.g., orders of magnitude. There is no HW or FW workaround for this problem. The bug is very easy to reproduce on a loaded system. Here is an example on a Haswell client, where CPU0, CPU4 are siblings. We load the CPUs with a simple triad app streaming large floating-point vector. We use 0x81d0 corrupting event (MEM_UOPS_RETIRED:ALL_LOADS) and 0x20cc (ROB_MISC_EVENTS:LBR_INSERTS). Given we are not using the LBR, the 0x20cc event should be zero. $ taskset -c 0 triad & $ taskset -c 4 triad & $ perf stat -a -C 0 -e r81d0 sleep 100 & $ perf stat -a -C 4 -r20cc sleep 10 Performance counter stats for 'system wide': 139 277 291 r20cc 10,000969126 seconds time elapsed In this example, 0x81d0 and r20cc ar eusing sinling counters on CPU0 and CPU4. 0x81d0 leaks into 0x20cc and corrupts it from 0 to 139 millions occurrences. This patch provides a software workaround to this problem by modifying the way events are scheduled onto counters by the kernel. The patch forces cross-thread mutual exclusion between counters in case a corrupting event is measured by one of the hyper-threads. If thread 0, counter 0 is measuring event 0xd0, then nothing can be measured on counter 0, thread 1. If no corrupting event is measured on any hyper-thread, event scheduling proceeds as before. The same example run with the workaround enabled, yield the correct answer: $ taskset -c 0 triad & $ taskset -c 4 triad & $ perf stat -a -C 0 -e r81d0 sleep 100 & $ perf stat -a -C 4 -r20cc sleep 10 Performance counter stats for 'system wide': 0 r20cc 10,000969126 seconds time elapsed The patch does provide correctness for all non-corrupting events. It does not "repatriate" the leaked counts back to the leaking counter. This is planned for a second patch series. This patch series makes this repatriation more easy by guaranteeing the sibling counter is not measuring any useful event. The patch introduces dynamic constraints for events. That means that events which did not have constraints, i.e., could be measured on any counters, may now be constrained to a subset of the counters depending on what is going on the sibling thread. The algorithm is similar to a cache coherency protocol. We call it XSU in reference to Exclusive, Shared, Unused, the 3 possible states of a PMU counter. As a consequence of the workaround, users may see an increased amount of event multiplexing, even in situtations where there are fewer events than counters measured on a CPU. Patch has been tested on all three impacted processors. Note that when HT is off, there is no corruption. However, the workaround is still enabled, yet not costing too much. Adding a dynamic detection of HT on turned out to be complex are requiring too much to code to be justified. This patch addresses the issue when PEBS is not used. A subsequent patch fixes the problem when PEBS is used. Signed-off-by: NMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com> [spinlock_t -> raw_spinlock_t] Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NStephane Eranian <eranian@google.com> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1416251225-17721-7-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Maria Dimakopoulou 提交于
This patch adds a new shared_regs style structure to the per-cpu x86 state (cpuc). It is used to coordinate access between counters which must be used with exclusion across HyperThreads on Intel processors. This new struct is not needed on each PMU, thus is is allocated on demand. Signed-off-by: NMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com> [peterz: spinlock_t -> raw_spinlock_t] Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NStephane Eranian <eranian@google.com> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1416251225-17721-6-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Stephane Eranian 提交于
This patch adds an index parameter to the get_event_constraint() x86_pmu callback. It is expected to represent the index of the event in the cpuc->event_list[] array. When the callback is used for fake_cpuc (evnet validation), then the index must be -1. The motivation for passing the index is to use it to index into another cpuc array. Signed-off-by: NStephane Eranian <eranian@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Cc: maria.n.dimakopoulou@gmail.com Link: http://lkml.kernel.org/r/1416251225-17721-5-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Stephane Eranian 提交于
Make the cpuc->kfree_on_online a vector to accommodate more than one entry and add the second entry to be used by a later patch. Signed-off-by: NStephane Eranian <eranian@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1416251225-17721-3-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Stephane Eranian 提交于
Because it will be used for more than just tracking the presence of extra registers. Signed-off-by: NStephane Eranian <eranian@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: bp@alien8.de Cc: jolsa@redhat.com Cc: kan.liang@intel.com Cc: maria.n.dimakopoulou@gmail.com Link: http://lkml.kernel.org/r/1416251225-17721-2-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Alexander Shishkin 提交于
Add support for Branch Trace Store (BTS) via kernel perf event infrastructure. The difference with the existing implementation of BTS support is that this one is a separate PMU that exports events' trace buffers to userspace by means of AUX area of the perf buffer, which is zero-copy mapped into userspace. The immediate benefit is that the buffer size can be much bigger, resulting in fewer interrupts and no kernel side copying is involved and little to no trace data loss. Also, kernel code can be traced with this driver. The old way of collecting BTS traces still works. Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kaixu Xia <kaixu.xia@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Robert Richter <rric@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: markus.t.metzger@intel.com Cc: mathieu.poirier@linaro.org Link: http://lkml.kernel.org/r/1422614435-114702-1-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Alexander Shishkin 提交于
Add support for Intel Processor Trace (PT) to kernel's perf events. PT is an extension of Intel Architecture that collects information about software execuction such as control flow, execution modes and timings and formats it into highly compressed binary packets. Even being compressed, these packets are generated at hundreds of megabytes per second per core, which makes it impractical to decode them on the fly in the kernel. This driver exports trace data by through AUX space in the perf ring buffer, which is zero-copy mapped into userspace for faster data retrieval. Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kaixu Xia <kaixu.xia@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Robert Richter <rric@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: markus.t.metzger@intel.com Cc: mathieu.poirier@linaro.org Link: http://lkml.kernel.org/r/1422614392-114498-1-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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