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 096A7C74A5B for ; Thu, 23 Mar 2023 15:56:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231438AbjCWP4S (ORCPT ); Thu, 23 Mar 2023 11:56:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231705AbjCWP4R (ORCPT ); Thu, 23 Mar 2023 11:56:17 -0400 Received: from mail-qt1-x82d.google.com (mail-qt1-x82d.google.com [IPv6:2607:f8b0:4864:20::82d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EEAB21A08 for ; Thu, 23 Mar 2023 08:56:15 -0700 (PDT) Received: by mail-qt1-x82d.google.com with SMTP id w25so4498264qtc.5 for ; Thu, 23 Mar 2023 08:56:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; t=1679586974; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=73H5IIveVwCSuj8ISfgz0DD6tM9W3+Bkt6XVlPhAYGQ=; b=BOTN3RHikvmNyJ/5BRIscfqCjptXrf8qpEubjPg0OC/Xwy+boUt94/+OfrbOvrjrzs cJmWGbxdzfNwYKXLNjFeE4gMQoT6n7Ue/HEG5/LMoEeTKeSw/uGUVJVLhA+eCCAdPAw6 TtqrrK35mvYRbzkyskIxNy5mDJm9BfKY9K6UzVcc3DGVU9OzF+09jvq6Drjb5mZ2qmVt HenjMS5dF/r4y3zFsqrBc6Pye1BCCpqXxrBcHNF0Eo2mmCOm0/3b/V5FU143KRmBza1U 0t4zXTHbwVZfvfVGehbwYOD9++M2yfXXjOlk6zzl04FgUWlZQ7+y/4hEPkd/CR7pqYbK NovA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679586974; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=73H5IIveVwCSuj8ISfgz0DD6tM9W3+Bkt6XVlPhAYGQ=; b=vX8zfmm03Xi+mcZM2kBCBPKnXH2ok+4cX5qriuIZJC/EeEveXkBxoCmXhtAK9ajRxu DnW/xD2OwbqGHd3qVLzJUJk/h5uWhLWVPdaeZLzYhLl9WwrTDKs9l7OgC4YFNqOxAPi4 nldBUWEm3KXFOKZMSQa71r34lKZ8UT6rGDOk/cfJwjTzt60vlVo6LqVfBBpvUbvCibJn PjTNfi1bNTXvY9oikoQxC+bV4+fndb6/1EwKYknm9lqRr0oYnD7hxiClGvbNHcDjuILH oQ5x4LGRi8IMpp5X7CvjRf1SxV8lbtS8TvlkDh9NO4WZDzLAZmlU/qhUNOp8teujDlBS +3aA== X-Gm-Message-State: AO0yUKXW76bMnaowaUzBv5aqw9n/QV+GYPT/NzlzB9C6XKhBL62MlVhq yAsPTXv03kK/fyx8c5h01bFIWA== X-Google-Smtp-Source: AK7set8ZHb51Enf0t/dIsgKw2woHO3ntBPTQ4bYWsu5XGHqtbaXdqba7YQaqZsTNXwWNIceHWF4QLA== X-Received: by 2002:ac8:5b87:0:b0:3b9:bc8c:c214 with SMTP id a7-20020ac85b87000000b003b9bc8cc214mr9815638qta.31.1679586974671; Thu, 23 Mar 2023 08:56:14 -0700 (PDT) Received: from localhost ([2620:10d:c091:400::5:62db]) by smtp.gmail.com with ESMTPSA id 201-20020a3708d2000000b007456efa7f73sm8647826qki.85.2023.03.23.08.56.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Mar 2023 08:56:14 -0700 (PDT) Date: Thu, 23 Mar 2023 11:56:13 -0400 From: Johannes Weiner To: Yosry Ahmed Cc: Tejun Heo , Josef Bacik , Jens Axboe , Zefan Li , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , Vasily Averin , cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org Subject: Re: [RFC PATCH 4/7] memcg: sleep during flushing stats in safe contexts Message-ID: <20230323155613.GC739026@cmpxchg.org> References: <20230323040037.2389095-1-yosryahmed@google.com> <20230323040037.2389095-5-yosryahmed@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230323040037.2389095-5-yosryahmed@google.com> Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, Mar 23, 2023 at 04:00:34AM +0000, Yosry Ahmed wrote: > @@ -644,26 +644,26 @@ static void __mem_cgroup_flush_stats(void) > return; > > flush_next_time = jiffies_64 + 2*FLUSH_TIME; > - cgroup_rstat_flush(root_mem_cgroup->css.cgroup, false); > + cgroup_rstat_flush(root_mem_cgroup->css.cgroup, may_sleep); How is it safe to call this with may_sleep=true when it's holding the stats_flush_lock? > atomic_set(&stats_flush_threshold, 0); > spin_unlock(&stats_flush_lock); > }