- 03 6月, 2009 1 次提交
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由 Paul Mackerras 提交于
Commit ef923214 ("perf_counter: powerpc: use u64 for event codes internally") introduced a bug where the return value from function find_alternative_bdecode gets put into a u64 variable and later tested to see if it is < 0. The effect is that we get extra, bogus event code alternatives on POWER5 and POWER5+, leading to error messages such as "oops compute_mmcr failed" being printed and counters not counting properly. This fixes it by using s64 for the return type of find_alternative_bdecode and for the local variable that the caller puts the value in. It also makes the event argument a u64 on POWER5+ for consistency. Signed-off-by: NPaul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Kacur <jkacur@redhat.com> Cc: Stephane Eranian <eranian@googlemail.com> LKML-Reference: <18982.17586.666132.90983@cargo.ozlabs.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 15 5月, 2009 2 次提交
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由 Paul Mackerras 提交于
This uses values from the MMCRA, SIAR and SDAR registers on powerpc to supply more precise information for overflow events, including a data address when PERF_RECORD_ADDR is specified. Since POWER6 uses different bit positions in MMCRA from earlier processors, this converts the struct power_pmu limited_pmc5_6 field, which only had 0/1 values, into a flags field and defines bit values for its previous use (PPMU_LIMITED_PMC5_6) and a new flag (PPMU_ALT_SIPR) to indicate that the processor uses the POWER6 bit positions rather than the earlier positions. It also adds definitions in reg.h for the new and old positions of the bit that indicates that the SIAR and SDAR values come from the same instruction. For the data address, the SDAR value is supplied if we are not doing instruction sampling. In that case there is no guarantee that the address given in the PERF_RECORD_ADDR subrecord will correspond to the instruction whose address is given in the PERF_RECORD_IP subrecord. If instruction sampling is enabled (e.g. because this counter is counting a marked instruction event), then we only supply the SDAR value for the PERF_RECORD_ADDR subrecord if it corresponds to the instruction whose address is in the PERF_RECORD_IP subrecord. Otherwise we supply 0. [ Impact: support more PMU hardware features on PowerPC ] Signed-off-by: NPaul Mackerras <paulus@samba.org> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <18955.37028.48861.555309@drongo.ozlabs.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Paul Mackerras 提交于
Although the perf_counter API allows 63-bit raw event codes, internally in the powerpc back-end we had been using 32-bit event codes. This expands them to 64 bits so that we can add bits for specifying threshold start/stop events and instruction sampling modes later. This also corrects the return value of can_go_on_limited_pmc; we were returning an event code rather than just a 0/1 value in some circumstances. That didn't particularly matter while event codes were 32-bit, but now that event codes are 64-bit it might, so this fixes it. [ Impact: extend PowerPC perfcounter interfaces from u32 to u64 ] Signed-off-by: NPaul Mackerras <paulus@samba.org> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <18955.36874.472452.353104@drongo.ozlabs.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 29 4月, 2009 1 次提交
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由 Paul Mackerras 提交于
POWER5+ and POWER6 have two hardware counters with limited functionality: PMC5 counts instructions completed in run state and PMC6 counts cycles in run state. (Run state is the state when a hardware RUN bit is 1; the idle task clears RUN while waiting for work to do and sets it when there is work to do.) These counters can't be written to by the kernel, can't generate interrupts, and don't obey the freeze conditions. That means we can only use them for per-task counters (where we know we'll always be in run state; we can't put a per-task counter on an idle task), and only if we don't want interrupts and we do want to count in all processor modes. Obviously some counters can't go on a limited hardware counter, but there are also situations where we can only put a counter on a limited hardware counter - if there are already counters on that exclude some processor modes and we want to put on a per-task cycle or instruction counter that doesn't exclude any processor mode, it could go on if it can use a limited hardware counter. To keep track of these constraints, this adds a flags argument to the processor-specific get_alternatives() functions, with three bits defined: one to say that we can accept alternative event codes that go on limited counters, one to say we only want alternatives on limited counters, and one to say that this is a per-task counter and therefore events that are gated by run state are equivalent to those that aren't (e.g. a "cycles" event is equivalent to a "cycles in run state" event). These flags are computed for each counter and stored in the counter->hw.counter_base field (slightly wonky name for what it does, but it was an existing unused field). Since the limited counters don't freeze when we freeze the other counters, we need some special handling to avoid getting skew between things counted on the limited counters and those counted on normal counters. To minimize this skew, if we are using any limited counters, we read PMC5 and PMC6 immediately after setting and clearing the freeze bit. This is done in a single asm in the new write_mmcr0() function. The code here is specific to PMC5 and PMC6 being the limited hardware counters. Being more general (e.g. having a bitmap of limited hardware counter numbers) would have meant more complex code to read the limited counters when freezing and unfreezing the normal counters, with conditional branches, which would have increased the skew. Since it isn't necessary for the code to be more general at this stage, it isn't. This also extends the back-ends for POWER5+ and POWER6 to be able to handle up to 6 counters rather than the 4 they previously handled. Signed-off-by: NPaul Mackerras <paulus@samba.org> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> LKML-Reference: <18936.19035.163066.892208@cargo.ozlabs.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 08 4月, 2009 1 次提交
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由 Paul Mackerras 提交于
Impact: enable access to hardware feature POWER processors have the ability to "mark" a subset of the instructions and provide more detailed information on what happens to the marked instructions as they flow through the pipeline. This marking is enabled by the "sample enable" bit in MMCRA, and there are synchronization requirements around setting and clearing the bit. This adds logic to the processor-specific back-ends so that they know which events relate to marked instructions and set the sampling enable bit if any event that we want to put on the PMU is a marked instruction event. It also adds logic to the generic powerpc code to do the necessary synchronization if that bit is set. Signed-off-by: NPaul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <18908.31930.1024.228867@cargo.ozlabs.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 06 3月, 2009 1 次提交
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由 Paul Mackerras 提交于
Impact: more hardware support This adds the back-end for the PMU on the POWER5+ processors (i.e. GS, including GS DD3 aka POWER5++). This doesn't use the fixed-function PMC5 and PMC6 since they don't respect the freeze conditions and don't generate interrupts, as on POWER6. Signed-off-by: NPaul Mackerras <paulus@samba.org>
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- 26 2月, 2009 1 次提交
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由 Paul Mackerras 提交于
This adds the back-end for the PMU on the POWER5 processor. This knows how to use the fixed-function PMC5 and PMC6 (instructions completed and run cycles). Unlike POWER6, PMC5/6 obey the freeze conditions and can generate interrupts, so their use doesn't impose any extra restrictions. POWER5+ is different and is not supported by this patch. Signed-off-by: NPaul Mackerras <paulus@samba.org>
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