From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 414E1C433E7 for ; Fri, 16 Oct 2020 16:26:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C66EF2084C for ; Fri, 16 Oct 2020 16:26:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="Rf5X8vXY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408563AbgJPQ0z (ORCPT ); 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201016142047.GS6756@twin.jikos.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 16.10.20 г. 17:20 ч., David Sterba wrote: > On Thu, Oct 08, 2020 at 03:24:30PM +0300, Nikolay Borisov wrote: >> If transaction_kthread is woken up before >> btrfs_fs_info::commit_interval seconds have elapsed it will sleep for a >> fixed period of 5 seconds. This is not a problem per-se but is not >> accuaret, instead the code should sleep for an interval which guarantees >> on next wakeup commit_interval would have passed. Since time tracking is >> not accurate add 1 second to ensure next wake up would be after >> commit_interval. >> >> Signed-off-by: Nikolay Borisov >> --- >> fs/btrfs/disk-io.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c >> index c5d3e7f75066..a1fe99cf0831 100644 >> --- a/fs/btrfs/disk-io.c >> +++ b/fs/btrfs/disk-io.c >> @@ -1735,7 +1735,7 @@ static int transaction_kthread(void *arg) >> if (cur->state < TRANS_STATE_COMMIT_START && >> delta < fs_info->commit_interval) { >> spin_unlock(&fs_info->trans_lock); >> - delay = msecs_to_jiffies(5000); >> + delay = msecs_to_jiffies((1+delta) * 1000); > > This does not seem right. Delta is number of seconds since the > transaction started, so we need to sleep for the remaining time. Which > is commit_interval - delta. Doh, you are right. The correct line should be : delay -= msecs_to_jiffies((1+delta) * 1000); The + 1 is needed so that upon next wake up we are guaranteed next delta is >= commit_interval. Shall I send a fixed patch or are you going to modify it and merge it? >