The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: ce0d998be9274dd3a3d971cbeaa6fe28fd2c3062 Gitweb: https://git.kernel.org/tip/ce0d998be9274dd3a3d971cbeaa6fe28fd2c3062 Author: Adrian Hunter adrian.hunter@intel.com AuthorDate: Sat, 12 Nov 2022 17:15:08 +02:00 Committer: Peter Zijlstra peterz@infradead.org CommitterDate: Wed, 16 Nov 2022 10:12:59 +01:00
perf/x86/intel/pt: Fix sampling using single range output
Deal with errata TGL052, ADL037 and RPL017 "Trace May Contain Incorrect Data When Configured With Single Range Output Larger Than 4KB" by disabling single range output whenever larger than 4KB.
Fixes: 670638477aed ("perf/x86/intel/pt: Opportunistically use single range output mode") Signed-off-by: Adrian Hunter adrian.hunter@intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20221112151508.13768-1-adrian.hunter@intel.com --- arch/x86/events/intel/pt.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 82ef87e..42a5579 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -1263,6 +1263,15 @@ static int pt_buffer_try_single(struct pt_buffer *buf, int nr_pages) if (1 << order != nr_pages) goto out;
+ /* + * Some processors cannot always support single range for more than + * 4KB - refer errata TGL052, ADL037 and RPL017. Future processors might + * also be affected, so for now rather than trying to keep track of + * which ones, just disable it for all. + */ + if (nr_pages > 1) + goto out; + buf->single = true; buf->nr_pages = nr_pages; ret = 0;