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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 24312C4727E for ; Thu, 1 Oct 2020 17:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C34122075F for ; Thu, 1 Oct 2020 17:00:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="nhlNWx9W" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732787AbgJARAo (ORCPT ); Thu, 1 Oct 2020 13:00:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:37986 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732213AbgJARAo (ORCPT ); Thu, 1 Oct 2020 13:00:44 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1601571642; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FBxjpUPAONJ+XqUQuZPU/FmGyoPMABIG8dYwepWTg9o=; b=nhlNWx9WKyL/R8ePbdgLs+VJsvxFk3kt2QqgvZxDohm1sNNcQukYleQjt8TxHMeHWc+KG4 Bpi0vvxmAB/rl2mmaVD2UwnbgRwMogFFKIU5CnqlDsIIRnpV/O/OjQGzd/rXf+d+3gZNmE d4L3k7kbRYqNo3CclC3b/kt+poFTwFA= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C78D4ADBB; Thu, 1 Oct 2020 17:00:42 +0000 (UTC) Date: Thu, 1 Oct 2020 19:00:36 +0200 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: Roman Gushchin Cc: Andrew Morton , Shakeel Butt , Johannes Weiner , Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com Subject: Re: [PATCH v4 4/4] mm: convert page kmemcg type to a page memcg flag Message-ID: <20201001170036.GA29848@blackbook> References: <20201001002710.748166-1-guro@fb.com> <20201001002710.748166-5-guro@fb.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="zYM0uCDKw75PZbzx" Content-Disposition: inline In-Reply-To: <20201001002710.748166-5-guro@fb.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --zYM0uCDKw75PZbzx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi. On Wed, Sep 30, 2020 at 05:27:10PM -0700, Roman Gushchin wrote: > @@ -369,8 +371,12 @@ enum page_memcg_data_flags { > */ > static inline struct mem_cgroup *page_memcg(struct page *page) > { > + unsigned long memcg_data = page->memcg_data; > + > VM_BUG_ON_PAGE(PageSlab(page), page); > - return (struct mem_cgroup *)page->memcg_data; > + VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_OBJCGS, page); > + > + return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); > } Shouldn't this change go also into page_memcg_rcu()? (I don't think the current single user (workingset_activation() would pass a non-slab kernel page but for consistency sake.) Alternatively, I'm thinking why (in its single use) is there page_memcg_rcu() a separate function to page_memcg() (cross memcg page migration?). Regards, Michal --zYM0uCDKw75PZbzx Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEEoQaUCWq8F2Id1tNia1+riC5qSgFAl92CywACgkQia1+riC5 qSiqEA//SFQ/WkWbKkYPDQ+OghC6osKkFtrUsL47bJda7RmwZBt8HEdVQF80bilH FT6WJF9TiSW7ezR3Gj6KrmHBKvy8vYOOiTRLv4qQG/ThSpGdrxlT7L9u1BMrWW0c 3aCNmHUGCpUU03dMaa9H8KfhPY6pRON/wz26at9xsGPgMkn0EBrzOA8WDBOxLhtS mVXj8wKPbX2UY8VewV6chYIlucx4joCnbw4xjbNcoW1+XJ6bglBWX0dS1dwz/hoV fLxdMdXlCs5fM53Xzqlv2BgHkV//l3oCUN2G8wi4EKSg+iit9mBRnYDPQ/pOXN7o uXWjxQBZMBxCt1Ct5avF3P/Af5CLhVbUPwsNItDlMTTZDoUV1/4drfH5uikMw4/k ORS9BkU2Bl1SFL6ivYtxFqSrEAbzzj2RuDyMBc6GnlvkNO8lva2wyCrPUuIFsDT9 W+88q8gNSq0B6MsiLfP6/cIqaesm/9lRIjEKmnRlD8x8B5lV/bMFa4C0wAOc6zyw yxxBD0b7cAVlRaBD/SADEzfEE+M9A36X/sgnl0LJSFKSozPgabUekUgoRSHkZLVw wfITwV7HvYux5uWXCeyIQI18iO45F9GDh/sArHiYCwQUVsri8QTNgJbn3dl4tNBu hE3nDTgseJJb6l0AFTepeiecNjTmvj0sT2vUSxHXjizC//zhVVI= =l/la -----END PGP SIGNATURE----- --zYM0uCDKw75PZbzx--