From nobody Wed Feb 11 02:09:46 2026 Received: from esa3.hgst.iphmx.com (esa3.hgst.iphmx.com [216.71.153.141]) (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 DE35931A57C; Mon, 20 Oct 2025 13:41:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.71.153.141 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760967696; cv=none; b=CFb+4bMhoc4zr+WPF18cFd5eN5A0ELgW0Ktr/CGkDYlWd/Nyohz93D2Ie9O0tj8spklXqwbEaeoBX94KLJE6E4u5hvppVmis3z/DdabLE+KIXRoU0AciSmFHJXN6MZa79IWTWyTsEIA1aDYfaj8XYVU0+gY6XyOjwIFDwbWSnsg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760967696; c=relaxed/simple; bh=ksy8BgshONcRNaaYPA2330I5SQCjqAYhB28T8Qj0gmc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZeEfn1lNUMgVDuTE8j7x48+QlAL4Di2hejW3Zrh4dlNQ6sktKs4qcfm0BPFs90Kj5rUBPm3Ncqx368x0Qq7+x2VLB6FqgNfDDQZSxf7orfyahjo9FdmlwBgdoK/gJagauW/OFhCbEDjSqKR7EDchR7sOrz2K6VQ4POZ7Fd7jQMw= 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=a9XTaoR/; arc=none smtp.client-ip=216.71.153.141 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="a9XTaoR/" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1760967695; x=1792503695; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ksy8BgshONcRNaaYPA2330I5SQCjqAYhB28T8Qj0gmc=; b=a9XTaoR/BUHIBVx1zYcmHRrzVkt4B8mVX+KquJYOHdG2lfHbgS7o3t0n 68I+3KMRH4yO9pklE+KCGKqAZlr35GDNwV5AUCHZwN/orUu7dhobsqusv l/fROLzQMAAMTSUUc0XiJlvNXe3w5WsAtpu+sPUl/Jaw7R157PK145hFW c2L1zfkfZsJ/pPpYWv6xnv51WbFLVVbPXxBzMfYoz1yPShiwvZb3RIY8X E+WiNxUwDYjRIFcgCwBD+UUSyh9rQHgJ/uT4q/4+fPBCpDeVYjDdY2cHJ bVxMT2iT1w7uVAU3yNLtXPWk0P38clLBF6DJaKuFgecgnykQInvLYeYRy A==; X-CSE-ConnectionGUID: PDYYkpruTS6tohk+tbh3Xg== X-CSE-MsgGUID: vF/NfaegRsW5hyANDUqJ/w== X-IronPort-AV: E=Sophos;i="6.19,242,1754928000"; d="scan'208";a="134518614" Received: from uls-op-cesaip02.wdc.com (HELO uls-op-cesaep03.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 20 Oct 2025 21:41:35 +0800 IronPort-SDR: 68f63c0e_iCvjtP4832ENZ134+DLFEMn6UwBG/bPKtW/uUPDhXkmvxXN +NnFAa+YlVberqSeQTNINcw987HoTnkWgsxmbkg== Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep03.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 20 Oct 2025 06:41:34 -0700 WDCIronportException: Internal Received: from 1pgdl13.ad.shared (HELO neo.fritz.box) ([10.224.28.46]) by uls-op-cesaip02.wdc.com with ESMTP; 20 Oct 2025 06:41:30 -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 v4 01/16] blktrace: only calculate trace length once Date: Mon, 20 Oct 2025 15:41:08 +0200 Message-ID: <20251020134123.119058-2-johannes.thumshirn@wdc.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251020134123.119058-1-johannes.thumshirn@wdc.com> References: <20251020134123.119058-1-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 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