From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f66.google.com (mail-wr1-f66.google.com [209.85.221.66]) by mail19.linbit.com (LINBIT Mail Daemon) with ESMTP id C02404207A2 for ; Mon, 12 Oct 2020 17:44:03 +0200 (CEST) Received: by mail-wr1-f66.google.com with SMTP id n6so19423470wrm.13 for ; Mon, 12 Oct 2020 08:44:03 -0700 (PDT) Received: from soda.linbit (62-99-137-214.static.upcbusiness.at. [62.99.137.214]) by smtp.gmail.com with ESMTPSA id o4sm6947378wrv.8.2020.10.12.08.43.02 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 12 Oct 2020 08:43:02 -0700 (PDT) Resent-Message-ID: <20201012154301.GU2116@soda.linbit> Received: from mail-ed1-f65.google.com (mail-ed1-f65.google.com [209.85.208.65]) by mail19.linbit.com (LINBIT Mail Daemon) with ESMTP id 9B5D5420318 for ; Wed, 8 Jul 2020 09:59:27 +0200 (CEST) Received: by mail-ed1-f65.google.com with SMTP id e15so40857865edr.2 for ; Wed, 08 Jul 2020 00:59:27 -0700 (PDT) From: Guoqing Jiang To: axboe@kernel.dk Message-Id: <20200708075819.4531-2-guoqing.jiang@cloud.ionos.com> In-Reply-To: <20200708075819.4531-1-guoqing.jiang@cloud.ionos.com> References: <20200708075819.4531-1-guoqing.jiang@cloud.ionos.com> Cc: linux-block@vger.kernel.org, Guoqing Jiang , Philipp Reisner , Lars Ellenberg , drbd-dev@lists.linbit.com Subject: [Drbd-dev] [PATCH RFC 1/5] block: return ns precision from disk_start_io_acct List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Date: Mon, 12 Oct 2020 15:45:45 -0000 Currently the duration accounting of bio based driver is converted from jiffies to ns, means it could be less accurate as request based driver. So let disk_start_io_acct return from ns precision, instead of convert jiffies to ns in disk_end_io_acct. Cc: Philipp Reisner Cc: Lars Ellenberg Cc: drbd-dev@lists.linbit.com Signed-off-by: Guoqing Jiang --- block/blk-core.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index d9d632639bd1..0e806a8c62fb 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1466,6 +1466,7 @@ unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, struct hd_struct *part = &disk->part0; const int sgrp = op_stat_group(op); unsigned long now = READ_ONCE(jiffies); + unsigned long start_ns = ktime_get_ns(); part_stat_lock(); update_io_ticks(part, now, false); @@ -1474,7 +1475,7 @@ unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, part_stat_local_inc(part, in_flight[op_is_write(op)]); part_stat_unlock(); - return now; + return start_ns; } EXPORT_SYMBOL(disk_start_io_acct); @@ -1484,11 +1485,11 @@ void disk_end_io_acct(struct gendisk *disk, unsigned int op, struct hd_struct *part = &disk->part0; const int sgrp = op_stat_group(op); unsigned long now = READ_ONCE(jiffies); - unsigned long duration = now - start_time; + unsigned long duration = ktime_get_ns() - start_time; part_stat_lock(); update_io_ticks(part, now, true); - part_stat_add(part, nsecs[sgrp], jiffies_to_nsecs(duration)); + part_stat_add(part, nsecs[sgrp], duration); part_stat_local_dec(part, in_flight[op_is_write(op)]); part_stat_unlock(); } -- 2.17.1