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authorAdrian Hunter <adrian.hunter@intel.com>2022-11-12 17:15:08 +0200
committerPeter Zijlstra <peterz@infradead.org>2022-11-16 10:12:59 +0100
commitce0d998be9274dd3a3d971cbeaa6fe28fd2c3062 (patch)
tree9c4b32dbbd1f213a02ecf48b20fe33f2b49a3c30 /arch/x86/events
parentbaa014b9543c8e5e94f5d15b66abfe60750b8284 (diff)
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
Diffstat (limited to 'arch/x86/events')
-rw-r--r--arch/x86/events/intel/pt.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 82ef87e9a897..42a55794004a 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;