From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: [PATCH 2/3] perf script: Fix off by one in brstackinsn IPC computation Date: Thu, 11 Jul 2019 11:19:21 -0700 Message-ID: <20190711181922.18765-2-andi@firstfloor.org> References: <20190711181922.18765-1-andi@firstfloor.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190711181922.18765-1-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org To: acme@kernel.org Cc: jolsa@kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Andi Kleen , Denis Bakhvalov List-Id: linux-perf-users.vger.kernel.org From: Andi Kleen When we hit the end of a program block, need to count the last instruction too for the IPC computation. This caused large errors for small blocks. % perf script -b ls / > /dev/null Before: % perf script -F +brstackinsn --xed ... 00007f94c9ac70d8 jz 0x7f94c9ac70e3 # PRED 3 cycles [36] 4.33 IPC 00007f94c9ac70e3 testb $0x20, 0x31d(%rbx) 00007f94c9ac70ea jnz 0x7f94c9ac70b0 00007f94c9ac70ec testb $0x8, 0x205ad(%rip) 00007f94c9ac70f3 jz 0x7f94c9ac6ff0 # PRED 1 cycles [37] 3.00 IPC After: % perf script -F +brstackinsn --xed ... 00007f94c9ac70d8 jz 0x7f94c9ac70e3 # PRED 3 cycles [15] 4.67 IPC 00007f94c9ac70e3 testb $0x20, 0x31d(%rbx) 00007f94c9ac70ea jnz 0x7f94c9ac70b0 00007f94c9ac70ec testb $0x8, 0x205ad(%rip) 00007f94c9ac70f3 jz 0x7f94c9ac6ff0 # PRED 1 cycles [16] 4.00 IPC Suggested-by: Denis Bakhvalov Signed-off-by: Andi Kleen --- tools/perf/builtin-script.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 2f6232f1bfdc..9a63cb3442a9 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -1059,7 +1059,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample, printed += ip__fprintf_sym(ip, thread, x.cpumode, x.cpu, &lastsym, attr, fp); if (ip == end) { - printed += ip__fprintf_jump(ip, &br->entries[i], &x, buffer + off, len - off, insn, fp, + printed += ip__fprintf_jump(ip, &br->entries[i], &x, buffer + off, len - off, ++insn, fp, &total_cycles); if (PRINT_FIELD(SRCCODE)) printed += print_srccode(thread, x.cpumode, ip); -- 2.20.1