| Message ID | 20210818171556.36912-3-kjain@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v4,1/3] powerpc/perf: Use stack siar instead of mfspr | expand |
| Related | show |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 25 jobs. |
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 23ec89a59893..b0a589409039 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -2251,15 +2251,9 @@ unsigned long perf_misc_flags(struct pt_regs *regs) */ unsigned long perf_instruction_pointer(struct pt_regs *regs) { - bool use_siar = regs_use_siar(regs); unsigned long siar = mfspr(SPRN_SIAR); - if (ppmu && (ppmu->flags & PPMU_P10_DD1)) { - if (siar) - return siar; - else - return regs->nip; - } else if (use_siar && siar_valid(regs)) + if (regs_use_siar(regs) && siar_valid(regs) && siar) return siar + perf_ip_adjust(regs); else return regs->nip;
Incase of random sampling, there can be scenarios where Sample Instruction Address Register(SIAR) may not latch to the sampled instruction and could result in the value of 0. In these scenarios it is preferred to return regs->nip. These corner cases are seen in the previous generation (p9) also. Patch adds the check for SIAR value along with regs_use_siar and siar_valid checks so that the function will return regs->nip incase SIAR is zero. Patch drops the code under PPMU_P10_DD1 flag check which handles SIAR 0 case only for Power10 DD1. Fixes: 2ca13a4cc56c9 ("powerpc/perf: Use regs->nip when SIAR is zero") Signed-off-by: Kajol Jain <kjain@linux.ibm.com> --- Changelog: v3 -> v4 - Remove use_siar variable and directly using regs_use_siar call as suggested by Christophe Leroy v2 -> v3 - Drop adding new ternary condition to check siar value. - Remove siar check specific for PPMU_P10_DD1 and add it along with common checks as suggested by Christophe Leroy and Michael Ellermen arch/powerpc/perf/core-book3s.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)