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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44F84EB64DD for ; Mon, 3 Jul 2023 10:17:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231199AbjGCKRQ (ORCPT ); Mon, 3 Jul 2023 06:17:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231287AbjGCKRF (ORCPT ); Mon, 3 Jul 2023 06:17:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B68B9C9; Mon, 3 Jul 2023 03:17:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 47A1360EAD; Mon, 3 Jul 2023 10:17:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27205C433C9; Mon, 3 Jul 2023 10:16:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688379422; bh=Ny5BGLb0fUO45nms2Ulce0zlZ8XNNtXNnuA6dwqjEBI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=N48t31dmHrvPkjWqY/Baq5NMlwFHpF/7g/ejXfLwkkPN42h5TOXItvma+bxHIp+jm Be0k1GcbbozhqawxgxQ9ckWmybPEkUlvoR9e3y1UyKVALxXzW/pPdkR9hHqr/iSdT4 KtIfKN2z/s/hK/pY0Q2lVADesdGmfW/yun/6rNax7EQfnaHXhp7uGAetlmtb6hRiFF 9pVWWJ+WHTLS+XS6sXe/ol5Nn/BuiOV3HkRU1rK+AcUuxMlj0YftQB0xU7RSHNZe3q YdkBiGSeWYiXLYG+WOf3YVelcAYE+XuLl6TwnNB5nt1TDV7sYP7EF9CUqrn7ooo++S butW0UvCnz+qA== Date: Mon, 3 Jul 2023 12:16:57 +0200 From: Christian Brauner To: Andrew Yang , linux-mm@kvack.org Cc: Alexander Viro , Matthias Brugger , AngeloGioacchino Del Regno , wsd_upstream@mediatek.com, casper.li@mediatek.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Matthew Wilcox Subject: Re: [PATCH] fs: drop_caches: draining pages before dropping caches Message-ID: <20230703-freifahrt-dachwohnung-49d858588e88@brauner> References: <20230630092203.16080-1-andrew.yang@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230630092203.16080-1-andrew.yang@mediatek.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Really more suitable for -mm to review. On Fri, Jun 30, 2023 at 05:22:02PM +0800, Andrew Yang wrote: > We expect a file page access after dropping caches should be a major > fault, but sometimes it's still a minor fault. That's because a file > page can't be dropped if it's in a per-cpu pagevec. Draining all pages > from per-cpu pagevec to lru list before trying to drop caches. > > Signed-off-by: Andrew Yang > --- > fs/drop_caches.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/drop_caches.c b/fs/drop_caches.c > index e619c31b6bd9..b9575957a7c2 100644 > --- a/fs/drop_caches.c > +++ b/fs/drop_caches.c > @@ -10,6 +10,7 @@ > #include > #include > #include > +#include > #include "internal.h" > > /* A global variable is a bit ugly, but it keeps the code simple */ > @@ -59,6 +60,7 @@ int drop_caches_sysctl_handler(struct ctl_table *table, int write, > static int stfu; > > if (sysctl_drop_caches & 1) { > + lru_add_drain_all(); > iterate_supers(drop_pagecache_sb, NULL); > count_vm_event(DROP_PAGECACHE); > } > -- > 2.18.0 >