From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52A053AB298; Thu, 4 Jun 2026 21:49:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780609775; cv=none; b=mYaodILeVaes1qLPGYWNYXHLL/wCPO2/w63A3fHbvXiH22b34JpLbz7in/UayyjrcseTJFcCxFzYosLgszy6KkWxWxVmV/6AwN5fuTo3+w42y7AhOjSPIef5qgyFnTYQD/6jSGKHdshJ8ywFiI0wvVBYVCYsxa0wH58607U0agc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780609775; c=relaxed/simple; bh=v99ERl0mvlavTFiAOqQv/oE8nGh7o84bP2ip0E5pQ3I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ijQy5yk3uA3oZBi8V5Yi7uvD+Zl1K7Oy3detSEnKAWZ89zObzFb860/PAXCVnemQAEnRvBgFO4PwiTlh0w1v7nHJpsjL+yrQ0IHI4m1juYbfnfKKel5Ama/s5JIpCpkMQ+HOIrljmKTKvwTWD2V8GU6Y27ZBUCYchdhsQo+gD5Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JSTR/qyK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JSTR/qyK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BED571F00893; Thu, 4 Jun 2026 21:49:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780609774; bh=5UAw5XE5RZgXmMye4BK+b2VKFEwiLzlKG3Am1FCVSlA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JSTR/qyKXXK8Oehbr+uNLKsFkv+0ZzkPK27s/ZLBsR+Kwl85XejfKGhdSpqfLPpGR fjeSJrorDIABTejer2c1X2dgkg8c560n0pFhy+tdHdwWwAaHi8Z6HBgIBSL10tFdmG zwTdFn9JCCB65SWr5jRIuAk3TYSal7XZRcGSW0h63vSvz7kCGZqchRJ9yEi4tJShQz NvjvYghnlvSe3vnMac3cIsJt/y5VDXN5L9dEJJ8cbIm9djOjB0w8Ixo76xiAsGjOgm myu9mItnxyQEAOkz0/skUa4Qy2BDafBXDNKOEE/ZoldEK5dzgUGTVF+EZOMZi8dp3u Tp3U7pDSf+LYg== From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Ian Rogers , Jiri Olsa , Adrian Hunter , James Clark , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org Subject: [PATCH v2 4/4] perf timechart: Remove unnecessary copy of backtrace Date: Thu, 4 Jun 2026 14:49:30 -0700 Message-ID: <20260604214931.2202322-5-namhyung@kernel.org> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog In-Reply-To: <20260604214931.2202322-1-namhyung@kernel.org> References: <20260604214931.2202322-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The pattern of strdup() and free() is found, and I think it just can use the original backtrace directly. Signed-off-by: Namhyung Kim --- tools/perf/builtin-timechart.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c index 4efac73a714c5e5f..04dbb944a42720b4 100644 --- a/tools/perf/builtin-timechart.c +++ b/tools/perf/builtin-timechart.c @@ -300,7 +300,7 @@ static void pid_put_sample(struct timechart *tchart, int pid, int type, sample->type = type; sample->next = c->samples; sample->cpu = cpu; - sample->backtrace = backtrace ? strdup(backtrace) : NULL; + sample->backtrace = backtrace; c->samples = sample; if (sample->type == TYPE_RUNNING && end > start && start > 0) { @@ -429,12 +429,14 @@ static void sched_wakeup(struct timechart *tchart, int cpu, u64 timestamp, struct per_pid *p; struct wake_event *we = zalloc(sizeof(*we)); - if (!we) + if (!we) { + free((char *)backtrace); return; + } we->time = timestamp; we->waker = waker; - we->backtrace = backtrace ? strdup(backtrace) : NULL; + we->backtrace = backtrace; if ((flags & TRACE_FLAG_HARDIRQ) || (flags & TRACE_FLAG_SOFTIRQ)) we->waker = -1; @@ -461,20 +463,28 @@ static void sched_switch(struct timechart *tchart, int cpu, u64 timestamp, const char *backtrace) { struct per_pid *p = NULL, *prev_p; + bool backtrace_used = false; prev_p = find_create_pid(tchart, prev_pid); p = find_create_pid(tchart, next_pid); - if (prev_p->current && prev_p->current->state != TYPE_NONE) + if (prev_p->current && prev_p->current->state != TYPE_NONE) { pid_put_sample(tchart, prev_pid, TYPE_RUNNING, cpu, prev_p->current->state_since, timestamp, backtrace); + backtrace_used = true; + } if (p && p->current) { - if (p->current->state != TYPE_NONE) + if (p->current->state != TYPE_NONE) { + if (backtrace && backtrace_used) + backtrace = strdup(backtrace); + pid_put_sample(tchart, next_pid, p->current->state, cpu, p->current->state_since, timestamp, backtrace); + backtrace_used = true; + } p->current->state_since = timestamp; p->current->state = TYPE_RUNNING; @@ -488,6 +498,9 @@ static void sched_switch(struct timechart *tchart, int cpu, u64 timestamp, if (prev_state == 0) prev_p->current->state = TYPE_WAITING; } + + if (!backtrace_used) + free((char *)backtrace); } /* @@ -655,7 +668,6 @@ process_sample_sched_wakeup(struct timechart *tchart, backtrace = cat_backtrace(sample, &tchart->session->machines.host); sched_wakeup(tchart, sample->cpu, sample->time, waker, wakee, flags, backtrace); - free((char *)backtrace); return 0; } @@ -678,7 +690,6 @@ process_sample_sched_switch(struct timechart *tchart, backtrace = cat_backtrace(sample, &tchart->session->machines.host); sched_switch(tchart, sample->cpu, sample->time, prev_pid, next_pid, prev_state, backtrace); - free((char *)backtrace); return 0; } -- 2.54.0.1032.g2f8565e1d1-goog