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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C821C433EF for ; Thu, 14 Apr 2022 20:43:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7EE656B0071; Thu, 14 Apr 2022 16:43:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 79BC06B0073; Thu, 14 Apr 2022 16:43:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 664266B0074; Thu, 14 Apr 2022 16:43:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id 546496B0071 for ; Thu, 14 Apr 2022 16:43:39 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 12E8039FE for ; Thu, 14 Apr 2022 20:43:39 +0000 (UTC) X-FDA: 79356660558.24.4375556 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf12.hostedemail.com (Postfix) with ESMTP id 6EF5B40005 for ; Thu, 14 Apr 2022 20:43:38 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A583461EFC; Thu, 14 Apr 2022 20:43:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E48DFC385A5; Thu, 14 Apr 2022 20:43:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1649969017; bh=pg7qUZdxd9rKGnl8ewo2PzP6w1T6jlwI6CT52Cxs9dI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=EfbN7CuumkY4po+UhvqGdXnRtzSvxQ3sPzxt3RlPeyZaMI0YVfUOdbdVzgpDfvnZr EWe8ynibbKkqFUKhw7Ek8iUgA/gtO8XvLz196hucwGxzR0WU/R+i0npEbpTliwWT8t pCVN7QddTCzyd10FiyyFcaF8dVSrVUA8dDThvsBo= Date: Thu, 14 Apr 2022 13:43:35 -0700 From: Andrew Morton To: Miaohe Lin Cc: , Subject: Re: [PATCH] mm/vmscan: fix comment for current_may_throttle Message-Id: <20220414134335.f58a0e13fb2083180a164c1d@linux-foundation.org> In-Reply-To: <20220414120202.30082-1-linmiaohe@huawei.com> References: <20220414120202.30082-1-linmiaohe@huawei.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: jfd7y1epesubkmpgewt1xebpzi9k6mzq X-Rspam-User: Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=EfbN7Cuu; dmarc=none; spf=pass (imf12.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 6EF5B40005 X-HE-Tag: 1649969018-297515 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, 14 Apr 2022 20:02:02 +0800 Miaohe Lin wrote: > Since commit 6d6435811c19 ("remove bdi_congested() and wb_congested() and > related functions"), there is no congested backing device check anymore. > Correct the comment accordingly. > > ... > > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2334,8 +2334,7 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, > /* > * If a kernel thread (such as nfsd for loop-back mounts) services > * a backing device by writing to the page cache it sets PF_LOCAL_THROTTLE. > - * In that case we should only throttle if the backing device it is > - * writing to is congested. In other cases it is safe to throttle. > + * In that case we should not throttle it otherwise it is safe to do so. > */ > static int current_may_throttle(void) > { That's a bit awkward to read. I tweaked it, and reflowed the comment to 80 cols. --- a/mm/vmscan.c~mm-vmscan-fix-comment-for-current_may_throttle-fix +++ a/mm/vmscan.c @@ -2332,9 +2332,9 @@ static unsigned int move_pages_to_lru(st } /* - * If a kernel thread (such as nfsd for loop-back mounts) services - * a backing device by writing to the page cache it sets PF_LOCAL_THROTTLE. - * In that case we should not throttle it otherwise it is safe to do so. + * If a kernel thread (such as nfsd for loop-back mounts) services a backing + * device by writing to the page cache it sets PF_LOCAL_THROTTLE. In this case + * we should not throttle. Otherwise it is safe to do so. */ static int current_may_throttle(void) { _