From: Kajol Jain <kjain@linux.ibm.com>
To: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
christophe.leroy@csgroup.eu
Cc: kjain@linux.ibm.com, atrajeev@linux.vnet.ibm.com,
maddy@linux.ibm.com, rnsastry@linux.ibm.com
Subject: [PATCH v4 1/3] powerpc/perf: Use stack siar instead of mfspr
Date: Wed, 18 Aug 2021 22:45:54 +0530 [thread overview]
Message-ID: <20210818171556.36912-1-kjain@linux.ibm.com> (raw)
Minor optimization in the 'perf_instruction_pointer' function code by
making use of stack siar instead of mfspr.
Fixes: 75382aa72f06 ("powerpc/perf: Move code to select SIAR or pt_regs
into perf_read_regs")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
---
arch/powerpc/perf/core-book3s.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index bb0ee716de91..1b464aad29c4 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2260,7 +2260,7 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
else
return regs->nip;
} else if (use_siar && siar_valid(regs))
- return mfspr(SPRN_SIAR) + perf_ip_adjust(regs);
+ return siar + perf_ip_adjust(regs);
else if (use_siar)
return 0; // no valid instruction pointer
else
--
2.26.2
next reply other threads:[~2021-08-18 17:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-18 17:15 Kajol Jain [this message]
2021-08-18 17:15 ` [PATCH v4 2/3] powerpc/perf: Drop the case of returning 0 as instruction pointer Kajol Jain
2021-08-18 17:15 ` [PATCH v4 3/3] powerpc/perf: Fix the check for SIAR value Kajol Jain
2021-08-19 5:52 ` [PATCH v4 1/3] powerpc/perf: Use stack siar instead of mfspr Nageswara Sastry
2021-08-27 13:16 ` Michael Ellerman
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