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| author | Stephane Eranian <eranian@google.com> | 2022-09-28 11:40:43 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-09-29 12:20:57 +0200 |
| commit | 3f9a1b3591003b122a6ea2d69f89a0fd96ec58b9 (patch) | |
| tree | bee8e3918c57f7e42f8bc3fd9c94ffed86f1d98c /kernel/kexec.c | |
| parent | 117ceeb1f4f87331e45a77e71f18303d15ec882e (diff) | |
| download | linux-3f9a1b3591003b122a6ea2d69f89a0fd96ec58b9.tar.gz linux-3f9a1b3591003b122a6ea2d69f89a0fd96ec58b9.tar.bz2 linux-3f9a1b3591003b122a6ea2d69f89a0fd96ec58b9.zip | |
perf/x86/amd/lbr: Adjust LBR regardless of filtering
In case of fused compare and taken branch instructions, the AMD LBR points to
the compare instruction instead of the branch. Users of LBR usually expects
the from address to point to a branch instruction. The kernel has code to
adjust the from address via get_branch_type_fused(). However this correction
is only applied when a branch filter is applied. That means that if no
filter is present, the quality of the data is lower.
Fix the problem by applying the adjustment regardless of the filter setting,
bringing the AMD LBR to the same level as other LBR implementations.
Fixes: 245268c19f70 ("perf/x86/amd/lbr: Use fusion-aware branch classifier")
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20220928184043.408364-3-eranian@google.com
Diffstat (limited to 'kernel/kexec.c')
0 files changed, 0 insertions, 0 deletions