Messages in this thread | | | From | Alexander Shishkin <> | Subject | Re: [PATCH] perf/x86/intel/pt: Allow disabling branch tracing | Date | Mon, 06 Feb 2017 18:05:29 +0200 |
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Andi Kleen <andi@firstfloor.org> writes:
> Alexander Shishkin <alexander.shishkin@linux.intel.com> writes: > >> Now that Intel PT supports more types of trace content than just branch >> tracing, it may be useful to allow the user to disable branch tracing >> when it is not needed. >> >> The special case is BDW, where not setting BranchEn is not supported. >> >> This is slightly trickier than necessary, because up to this moment >> the driver has been setting BranchEn automatically and the userspace >> assumes as much. Instead of reversing the semantics of BranchEn, we >> introduce a 'passthrough' bit, which will forego the default and allow >> the user to set BranchEn to their heart's content. > > cpu/passthrough=1,branchen=1/ seems far uglier/more complicanted to me > than the original cpu/nobranch=1/
It's /passthrough=1,branch=0/ or simply /passthrough=1/.
Regards, -- Alex
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