From nobody Tue Feb 10 19:10:22 2026 Received: from esa6.hgst.iphmx.com (esa6.hgst.iphmx.com [216.71.154.45]) (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 0AC3633EB01; Wed, 22 Oct 2025 11:41:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.71.154.45 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761133291; cv=none; b=WHF/g/VMOlUk8UJ5kMLaUz3ALzNAMMlXKLCUaB2j7Nk5YmdnwftH8m4QuGLlsoa0KahYdVDxNO8/IBB2LSFqn5jUsEltYVsHXjEYsiHQs6NBER0iQNeWbgZQOhUBsqWxdDjAFI6v0LfwdzG2tYZ274dEbO7/BJg0RNAap7ZWCJc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761133291; c=relaxed/simple; bh=ADgSVbzcBq0V5YuQtV/YJ3D05FWKwC8OY4ZG3MiehRk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=INjQCEp4kKGLRGVy0yvKa0uOEiGwo0XA0AWus6D7jTuWCABjsto9F2N1Gn70gyyMUkgl42xNgXwbHbsKKmXlyHPKlhmCg7VnMscnzn7ULhmOTv4Ki8pSzGWHJ9FBR9YoBt2SdZN+rDarp5f978Fxa9p8Jfo0Nzt84xkOailclGs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com; spf=pass smtp.mailfrom=wdc.com; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b=g0/fIfVx; arc=none smtp.client-ip=216.71.154.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wdc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="g0/fIfVx" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1761133290; x=1792669290; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ADgSVbzcBq0V5YuQtV/YJ3D05FWKwC8OY4ZG3MiehRk=; b=g0/fIfVxrJovzoXaiNlwzeNBkzWdnHaCKOtNPgx7cyrwKO48XJ0jO44y XMUUSQe8VJKbATmyuDz1j3xC7+CxN8dIMi7cLe+efEYReuvDY7Qj+LzmK 6v/7dFDYqDnRNrkfLezw5VOC19wYHBIW0q8oIWLor4yFADbT1o3HPgchy 8oa8RzJjxPRZiGj/K0pRJogIVviKW9PVxkMU/QWvwmzoeP9wNuC5tiieg ETqTahv9pj+BA6QYCwM0wP6KEEwMLA61Hs4tu9SlPQk3X2w6nSwtmhp1M 4WT3TSzpjAlqJ7IxPjhMwwakajcIT4IomOugtlWq2iAlUhK1PSWzf82Yj g==; X-CSE-ConnectionGUID: zJI2/K99SUyIiJuWvst3BA== X-CSE-MsgGUID: LVjD4RmGT7ShTTIjvvAXAA== X-IronPort-AV: E=Sophos;i="6.19,247,1754928000"; d="scan'208";a="133361403" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 22 Oct 2025 19:41:29 +0800 IronPort-SDR: 68f8c2e9_EXR0otZSTKDKSo0qtQhGpY8087xHMYWP68lM1Ff9PchOLAm e4Ohg912l6Bu/X5W0YxI4XfqGwH0SdUkQuVWJ/w== Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 22 Oct 2025 04:41:29 -0700 WDCIronportException: Internal Received: from unknown (HELO neo.wdc.com) ([10.224.28.49]) by uls-op-cesaip02.wdc.com with ESMTP; 22 Oct 2025 04:41:24 -0700 From: Johannes Thumshirn To: axboe@kernel.dk Cc: chaitanyak@nvidia.com, dlemoal@kernel.org, hare@suse.de, hch@lst.de, john.g.garry@oracle.com, linux-block@vger.kernel.org, linux-btrace@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, martin.petersen@oracle.com, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, naohiro.aota@wdc.com, rostedt@goodmis.org, shinichiro.kawasaki@wdc.com, Johannes Thumshirn Subject: [PATCH v5 01/16] blktrace: only calculate trace length once Date: Wed, 22 Oct 2025 13:41:00 +0200 Message-ID: <20251022114115.213865-2-johannes.thumshirn@wdc.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251022114115.213865-1-johannes.thumshirn@wdc.com> References: <20251022114115.213865-1-johannes.thumshirn@wdc.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" De-duplicate the calculation of the trace length instead of doing the calculation twice, once for calling trace_buffer_lock_reserve() and once for calling relay_reserve(). Reviewed-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Signed-off-by: Johannes Thumshirn --- kernel/trace/blktrace.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 6941145b5058..bc4b885f2cec 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -76,13 +76,14 @@ static void trace_note(struct blk_trace *bt, pid_t pid,= int action, int cpu =3D smp_processor_id(); bool blk_tracer =3D blk_tracer_enabled; ssize_t cgid_len =3D cgid ? sizeof(cgid) : 0; + size_t trace_len; =20 + trace_len =3D sizeof(*t) + cgid_len + len; if (blk_tracer) { buffer =3D blk_tr->array_buffer.buffer; trace_ctx =3D tracing_gen_ctx_flags(0); event =3D trace_buffer_lock_reserve(buffer, TRACE_BLK, - sizeof(*t) + len + cgid_len, - trace_ctx); + trace_len, trace_ctx); if (!event) return; t =3D ring_buffer_event_data(event); @@ -92,7 +93,7 @@ static void trace_note(struct blk_trace *bt, pid_t pid, i= nt action, if (!bt->rchan) return; =20 - t =3D relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len); + t =3D relay_reserve(bt->rchan, trace_len); if (t) { t->magic =3D BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; t->time =3D ktime_to_ns(ktime_get()); @@ -228,6 +229,7 @@ static void __blk_add_trace(struct blk_trace *bt, secto= r_t sector, int bytes, bool blk_tracer =3D blk_tracer_enabled; ssize_t cgid_len =3D cgid ? sizeof(cgid) : 0; const enum req_op op =3D opf & REQ_OP_MASK; + size_t trace_len; =20 if (unlikely(bt->trace_state !=3D Blktrace_running && !blk_tracer)) return; @@ -250,14 +252,14 @@ static void __blk_add_trace(struct blk_trace *bt, sec= tor_t sector, int bytes, return; cpu =3D raw_smp_processor_id(); =20 + trace_len =3D sizeof(*t) + pdu_len + cgid_len; if (blk_tracer) { tracing_record_cmdline(current); =20 buffer =3D blk_tr->array_buffer.buffer; trace_ctx =3D tracing_gen_ctx_flags(0); event =3D trace_buffer_lock_reserve(buffer, TRACE_BLK, - sizeof(*t) + pdu_len + cgid_len, - trace_ctx); + trace_len, trace_ctx); if (!event) return; t =3D ring_buffer_event_data(event); @@ -273,7 +275,7 @@ static void __blk_add_trace(struct blk_trace *bt, secto= r_t sector, int bytes, * from coming in and stepping on our toes. */ local_irq_save(flags); - t =3D relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_len); + t =3D relay_reserve(bt->rchan, trace_len); if (t) { sequence =3D per_cpu_ptr(bt->sequence, cpu); =20 --=20 2.51.0