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 261023E51C8; Wed, 24 Jun 2026 20:58:55 +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=1782334736; cv=none; b=eEQo2K1AyFF2Z633aZudatXavpznOvU1EZXCqAL6IXWDvY+tYpJjtUMfPt0WFL8fQrf+PaB4DLwcEdxdQK+mCyAcGy8qvBRehHUPX8KC5wLDewqiPQVqhpSGgJ02gRk4Pro7sTTUfZ78DLWXJ4dT0G/kmfQayVeXnH6665K9vOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782334736; c=relaxed/simple; bh=vW5vgJzW6VbffrsI52ciV4/HMmoKPgFAe4Xrg0n52So=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Zyx2+aav8n224sPjeSVPEj2JT8NfaNaK7D3hBW52vfQGGGEIKliAJgWR0ZJuz8Uz3NQlNjrJoUBhgDCDkAT760TtPwGBMezMyKELyVEprBIwoY4tYeCoH4UALDMM57fBGt/7pomfQ6qzg2DrudrptLGUCsPCw6oaX6Yo27lscxY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JzskP6DB; 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="JzskP6DB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A82AD1F00A3E; Wed, 24 Jun 2026 20:58:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782334735; bh=N839jw9SWgaUYVf04ONJUhtRVXvDxViEyzZcCUzWVz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JzskP6DB0Myj+3qO6Jlgp0U7h6BHDmxWpnupUCvOX5/pt6H/AbjWok+5FznoLWvP+ XyJYln7AiPn3mdLdbF0xKioFecxFBkSLuYn5OEjRtEtUIqBmRb2kbwB19/U+UtOyHN lrn0M7wGZC2m5W64Q5Tid09ZsmcPUpEsCz4dpYFj74EO+gmgb6ykkfTUYXxTnZ6I1U uT0U/JNI5K2v6RjLZ8iKauOtnMzI31ueZawHT6TGQunw9PRW3cGTFDn/IWBEGvOnK3 SlkTsCjyId2i3i2ijgfoqaZUbf2f6lXTo/MUmwrMbEKux0i+X8Phug/lff+zTTWK26 mUTWXkvA2Ga2A== 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 v3 4/8] perf timechart: Remove unnecessary copy of backtrace Date: Wed, 24 Jun 2026 13:58:30 -0700 Message-ID: <20260624205852.3864874-5-namhyung@kernel.org> X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog In-Reply-To: <20260624205852.3864874-1-namhyung@kernel.org> References: <20260624205852.3864874-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@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; } -- 2.55.0.rc0.799.gd6f94ed593-goog