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=-5.5 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT 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 A0812C43381 for ; Mon, 11 Mar 2019 17:14:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65D13205F4 for ; Mon, 11 Mar 2019 17:14:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="cbnTo9uh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727548AbfCKROG (ORCPT ); Mon, 11 Mar 2019 13:14:06 -0400 Received: from mail-yw1-f68.google.com ([209.85.161.68]:34610 "EHLO mail-yw1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726625AbfCKROF (ORCPT ); Mon, 11 Mar 2019 13:14:05 -0400 Received: by mail-yw1-f68.google.com with SMTP id x129so3532937ywc.1 for ; Mon, 11 Mar 2019 10:14:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=y58oEk6VFS6vSzvCUZ1rAopBEFvhw4rM0vVvFY79z3w=; b=cbnTo9uhVT9wL0/pDjHdpqDCQAmDqAAWTT5Y5z3BS8FgIRZRCmrMBSupLQtrmwiEU7 KNWY5PgO92GOlMjDPP0UOCN5cJxUoHP6F0cYtfYBH0kvGx0Df9p0KqeMeAinp7e6Hn7H qFeICoJOIUdbPnLvus51stmzJXaJ/+uInYfSGDOxkAxWBeJKtUvW2rdohxe2yz7qvTQ6 0O1D0M5XS3k4/pk8AY5EFdwCn5gOgS7J1ZsHZ45xqR571yERkeULGtH3An/Fy/czxlTE 94o1WvQc7t0r8iKPOxsSvgeCImOhz2aSP1OZVo2zCD6Jtc2HJuGJIQcB4TXESbv9wLGo hUUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=y58oEk6VFS6vSzvCUZ1rAopBEFvhw4rM0vVvFY79z3w=; b=l2FVBKH4oASXao64eC+Ytlck0YNm7Aa4bknIcWHrCy5GG48JMesa+KtrfPEK9SgSVh u23iPPcXZ6RVS0nkaYt0Ad+bUp3FKQSQ2kISfb9Kk3y/5iPsXWyFs+EMHThipDv/Uckc DlByEq4H4kb41on/Vn4zHXuZEKrLsDjiNLBIIF3G+gRvunSMU10xUwVj0ZwiW0tXI28p Pe8JkzhosBnNljnsZU39PYFsVdO3nZ+SMvAZ+i3jeqb+UehJlyJa4GZkQBd8iAI1nQ5L LlV6tTVfv7GgGf/ldeGPoqLhiNb+CBQPCW8DXDiojyCEYQkDNeDC9jXS0i5QpD/iRYdZ s2JA== X-Gm-Message-State: APjAAAWN5tpt9GXtCFIn3VOAHlJ2UoNIZagt/PSjYPPQRM8SjcGMmzbl ci/4ilJ2cro2u2TFuQ0/mxj4JA== X-Google-Smtp-Source: APXvYqwbksG6pV6NHQrSLAiG/AmNqN4B0KIeTZpNK2uAn6ch6pNfdQ5TPs6pHjzKEEq0BGkEHZCHyA== X-Received: by 2002:a81:a055:: with SMTP id x82mr26386742ywg.177.1552324444748; Mon, 11 Mar 2019 10:14:04 -0700 (PDT) Received: from localhost ([2620:10d:c091:200::1:3c60]) by smtp.gmail.com with ESMTPSA id j10sm1933530ywb.39.2019.03.11.10.14.03 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 11 Mar 2019 10:14:03 -0700 (PDT) Date: Mon, 11 Mar 2019 13:14:02 -0400 From: Johannes Weiner To: Roman Gushchin Cc: linux-mm@kvack.org, kernel-team@fb.com, linux-kernel@vger.kernel.org, Tejun Heo , Rik van Riel , Michal Hocko , Roman Gushchin Subject: Re: [PATCH 1/5] mm: prepare to premature release of memcg->vmstats_percpu Message-ID: <20190311171402.GA10823@cmpxchg.org> References: <20190307230033.31975-1-guro@fb.com> <20190307230033.31975-2-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190307230033.31975-2-guro@fb.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 07, 2019 at 03:00:29PM -0800, Roman Gushchin wrote: > Prepare to handle premature release of memcg->vmstats_percpu data. > Currently it's a generic pointer which is expected to be non-NULL > during the whole life time of a memcg. Switch over to the > rcu-protected pointer, and carefully check it for being non-NULL. > > This change is a required step towards dynamic premature release > of percpu memcg data. > > Signed-off-by: Roman Gushchin Acked-by: Johannes Weiner