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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2022-01-26 12:48:15 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-02-15 17:47:11 +0100 |
| commit | 161a9a33702a2e65a4118dacb449505ac8ce3122 (patch) | |
| tree | 2063cac219af871fb32240bb04756f2478dc0d58 /arch/x86/events | |
| parent | 28c24ded649cf068ca518f2a3d78f5e7e06d41d8 (diff) | |
| download | linux-161a9a33702a2e65a4118dacb449505ac8ce3122.tar.bz2 | |
perf/x86/intel/pt: Add a capability and config bit for disabling TNTs
As of Intel SDM (https://www.intel.com/sdm) version 076, there is a new
Intel PT feature called TNT-Disable which is enabled config bit 55.
TNT-Disable disables Taken-Not-Taken packets to reduce the tracing
overhead, but with the result that exact control flow information is
lost.
Add a capability and config bit for TNT-Disable.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20220126104815.2807416-3-adrian.hunter@intel.com
Diffstat (limited to 'arch/x86/events')
| -rw-r--r-- | arch/x86/events/intel/pt.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index f339c88d17f9..aa66c0c7b18b 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -60,6 +60,7 @@ static struct pt_cap_desc { PT_CAP(ptwrite, 0, CPUID_EBX, BIT(4)), PT_CAP(power_event_trace, 0, CPUID_EBX, BIT(5)), PT_CAP(event_trace, 0, CPUID_EBX, BIT(7)), + PT_CAP(tnt_disable, 0, CPUID_EBX, BIT(8)), PT_CAP(topa_output, 0, CPUID_ECX, BIT(0)), PT_CAP(topa_multiple_entries, 0, CPUID_ECX, BIT(1)), PT_CAP(single_range_output, 0, CPUID_ECX, BIT(2)), @@ -112,6 +113,7 @@ PMU_FORMAT_ATTR(noretcomp, "config:11" ); PMU_FORMAT_ATTR(ptw, "config:12" ); PMU_FORMAT_ATTR(branch, "config:13" ); PMU_FORMAT_ATTR(event, "config:31" ); +PMU_FORMAT_ATTR(notnt, "config:55" ); PMU_FORMAT_ATTR(mtc_period, "config:14-17" ); PMU_FORMAT_ATTR(cyc_thresh, "config:19-22" ); PMU_FORMAT_ATTR(psb_period, "config:24-27" ); @@ -121,6 +123,7 @@ static struct attribute *pt_formats_attr[] = { &format_attr_cyc.attr, &format_attr_pwr_evt.attr, &format_attr_event.attr, + &format_attr_notnt.attr, &format_attr_fup_on_ptw.attr, &format_attr_mtc.attr, &format_attr_tsc.attr, @@ -302,6 +305,7 @@ fail: RTIT_CTL_MTC | \ RTIT_CTL_PWR_EVT_EN | \ RTIT_CTL_EVENT_EN | \ + RTIT_CTL_NOTNT | \ RTIT_CTL_FUP_ON_PTW | \ RTIT_CTL_PTW_EN) @@ -360,6 +364,10 @@ static bool pt_event_valid(struct perf_event *event) !intel_pt_validate_hw_cap(PT_CAP_event_trace)) return false; + if (config & RTIT_CTL_NOTNT && + !intel_pt_validate_hw_cap(PT_CAP_tnt_disable)) + return false; + if (config & RTIT_CTL_PTW) { if (!intel_pt_validate_hw_cap(PT_CAP_ptwrite)) return false; |