2019-10-19 22:09:06

by Jiri Olsa

Subject: [PATCH] perf/x86/intel/pt: Fix base for single entry topa

Jan reported failing ltp test for pt. It looks like the reason
is commit 38bb8d77d0b9, that did not keep the TOPA_SHIFT for
entry base, adding it back.

[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/tracing/pt_test/pt_test.c

Reported-by: Jan Stancek <[email protected]>
Fixes: 38bb8d77d0b9 ("perf/x86/intel/pt: Split ToPA metadata and page layout")
Signed-off-by: Jiri Olsa <[email protected]>
---
arch/x86/events/intel/pt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 74e80ed9c6c4..05e43d0f430b 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -627,7 +627,7 @@ static struct topa *topa_alloc(int cpu, gfp_t gfp)
* link as the 2nd entry in the table
*/
if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries)) {
- TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p);
+ TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p) >> TOPA_SHIFT;
TOPA_ENTRY(&tp->topa, 1)->end = 1;
}

--
2.21.0

2019-10-20 12:46:17

by tip-bot2 for Alexey Makhalov

Subject: [tip: perf/urgent] perf/x86/intel/pt: Fix base for single entry topa

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID: 13301c6b16a6d809b331bb88e40ab9ce38238b8b
Gitweb: https://git.kernel.org/tip/13301c6b16a6d809b331bb88e40ab9ce38238b8b
Author: Jiri Olsa <[email protected]>
AuthorDate: Sun, 20 Oct 2019 00:07:26 +02:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Sun, 20 Oct 2019 14:42:28 +02:00

perf/x86/intel/pt: Fix base for single entry topa

Jan reported failing ltp test for PT:

https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/tracing/pt_test/pt_test.c

It looks like the reason is this new commit added in this v5.4 merge window:

38bb8d77d0b9 ("perf/x86/intel/pt: Split ToPA metadata and page layout")

which did not keep the TOPA_SHIFT for entry base.

Add it back.

Reported-by: Jan Stancek <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Fixes: 38bb8d77d0b9 ("perf/x86/intel/pt: Split ToPA metadata and page layout")
Link: https://lkml.kernel.org/r/[email protected]
[ Minor changelog edits. ]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/events/intel/pt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 74e80ed..05e43d0 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -627,7 +627,7 @@ static struct topa *topa_alloc(int cpu, gfp_t gfp)
* link as the 2nd entry in the table
*/
if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries)) {
- TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p);
+ TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p) >> TOPA_SHIFT;
TOPA_ENTRY(&tp->topa, 1)->end = 1;
}

2019-10-21 06:38:43

by Alexander Shishkin

Subject: Re: [PATCH] perf/x86/intel/pt: Fix base for single entry topa

Jiri Olsa <[email protected]> writes:

> Jan reported failing ltp test for pt. It looks like the reason
> is commit 38bb8d77d0b9, that did not keep the TOPA_SHIFT for
> entry base, adding it back.

Thanks for taking care of that so quickly!

Regards,
--
Alex