Searched hist:"405 b4537" (Results 1 – 2 of 2) sorted by relevance
/openbmc/linux/arch/x86/include/asm/ |
H A D | mmu_context.h | 405b4537 Sun Nov 24 23:48:38 CST 2019 Anthony Steinhauser <asteinhauser@google.com> perf/x86: Implement immediate enforcement of /sys/devices/cpu/rdpmc value of 0
When you successfully write 0 to /sys/devices/cpu/rdpmc, the RDPMC instruction should be disabled unconditionally and immediately (after you close the SYSFS file) by the documentation.
Instead, in the current implementation the PMU must be reloaded which happens only eventually some time in the future. Only after that the RDPMC instruction becomes disabled (on ring 3) on the respective core.
This change makes the treatment of the 0 value as blocking and as unconditional as the current treatment of the 2 value, only the CR4.PCE bit is naturally set to false instead of true.
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.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> Cc: acme@kernel.org Link: https://lkml.kernel.org/r/20191125054838.137615-1-asteinhauser@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org> 405b4537 Sun Nov 24 23:48:38 CST 2019 Anthony Steinhauser <asteinhauser@google.com> perf/x86: Implement immediate enforcement of /sys/devices/cpu/rdpmc value of 0 When you successfully write 0 to /sys/devices/cpu/rdpmc, the RDPMC instruction should be disabled unconditionally and immediately (after you close the SYSFS file) by the documentation. Instead, in the current implementation the PMU must be reloaded which happens only eventually some time in the future. Only after that the RDPMC instruction becomes disabled (on ring 3) on the respective core. This change makes the treatment of the 0 value as blocking and as unconditional as the current treatment of the 2 value, only the CR4.PCE bit is naturally set to false instead of true. Signed-off-by: Anthony Steinhauser <asteinhauser@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.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> Cc: acme@kernel.org Link: https://lkml.kernel.org/r/20191125054838.137615-1-asteinhauser@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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/openbmc/linux/arch/x86/events/ |
H A D | core.c | 405b4537 Sun Nov 24 23:48:38 CST 2019 Anthony Steinhauser <asteinhauser@google.com> perf/x86: Implement immediate enforcement of /sys/devices/cpu/rdpmc value of 0
When you successfully write 0 to /sys/devices/cpu/rdpmc, the RDPMC instruction should be disabled unconditionally and immediately (after you close the SYSFS file) by the documentation.
Instead, in the current implementation the PMU must be reloaded which happens only eventually some time in the future. Only after that the RDPMC instruction becomes disabled (on ring 3) on the respective core.
This change makes the treatment of the 0 value as blocking and as unconditional as the current treatment of the 2 value, only the CR4.PCE bit is naturally set to false instead of true.
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.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> Cc: acme@kernel.org Link: https://lkml.kernel.org/r/20191125054838.137615-1-asteinhauser@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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