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 A683EECAAA1 for ; Mon, 19 Sep 2022 21:37:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229974AbiISVhb (ORCPT ); Mon, 19 Sep 2022 17:37:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229962AbiISVhI (ORCPT ); Mon, 19 Sep 2022 17:37:08 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C61584D834 for ; Mon, 19 Sep 2022 14:36:25 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id g15-20020aa7874f000000b0053e8b9630c7so411697pfo.19 for ; Mon, 19 Sep 2022 14:36:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date; bh=gBPDRnXdyvF4xAXr245jZgfFcKRBxlvo8nsBRpPChFM=; b=pBQdFlYTW5SMJZLEMS2PIeY/jXnxQHmBdVPB0G13hsQ/jjd473V1RsISyxaNwQYjyP yH1LP0v5pq5LDRQLhpdkRO31sgmsuTaBoWRWpfl3oJObc2DyxrjOIJQRM78202UbhSDs I3YXeiX+4M9mVmC/jNaFEUhrogAJuDu88LJDMqkZifaAjpi+hYvR1xpnjM+HACqJ94bB LajxRGIq9aCsw8DTPeTOjXxhSvXNlH3t+YvGLSTEWAQ4/W3reGAiQWXWsg7YBT9/1i1f x7kIHKYQ/xdvouPjm2aKVRXkjRJtsiVBtIUblxJ9idoqr+i9hG1fedynPAQfkv10QNB9 TPhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date; bh=gBPDRnXdyvF4xAXr245jZgfFcKRBxlvo8nsBRpPChFM=; b=DgAWPAR4eKMtuZu0SF1Zr7O35puYf12VqIfttIY9IlG8EO0vx5559O/QzvWAFW+8zI auIXwxDVT0ZzDV7MgwvzEes4gmfy9ZC0ndMMFtqETyr68C9i5m0D2rpu7Pkt7nt+r9tf a64J+GJn0ve+VdT7Aw47agl7MAU/xNft3x0+A0lPAc542H7Oo9tjWZDa4Isp2/qk0KiH QOqhaAcZJyNL5SlnQL0NnlWUl/75dB9jK076Akm5paTF6SRGM1+orFoiPY1kyCSusCPk LR6+IWr+OILk2unxscIBQ36d4GT8SLP4WVPM/z7j4m2Aq7tMKxydYeRj+ZXMx0/wR5wP 7nVw== X-Gm-Message-State: ACrzQf3lmudzHlWM8WJrttKdx1oHkuStmn6RDqUpq3C9ZHK6HQxvGYCG IjfceIvxwa7LS6j0GHyOGQsyam4QXQ6xjQ== X-Google-Smtp-Source: AMsMyM5N8FWtYCLqNF0zfkdeNsEsbGZbL/ZlbqHTPultDwLR5KPcpZgvQuO9hx4F8/FG9yKpgr9DjPIcxlzz6A== X-Received: from shakeelb.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:262e]) (user=shakeelb job=sendgmr) by 2002:a17:90b:254a:b0:200:53f:891d with SMTP id nw10-20020a17090b254a00b00200053f891dmr246179pjb.168.1663623385293; Mon, 19 Sep 2022 14:36:25 -0700 (PDT) Date: Mon, 19 Sep 2022 21:36:22 +0000 In-Reply-To: <20220919180634.45958-2-ryncsn@gmail.com> Mime-Version: 1.0 References: <20220919180634.45958-1-ryncsn@gmail.com> <20220919180634.45958-2-ryncsn@gmail.com> Message-ID: <20220919213622.s3w2v2q7ktvbrpha@google.com> Subject: Re: [PATCH v2 1/2] mm: memcontrol: use memcg_kmem_enabled in count_objcg_event From: Shakeel Butt To: Kairui Song Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Andrew Morton , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 20, 2022 at 02:06:33AM +0800, Kairui Song wrote: > From: Kairui Song > > There are currently two helpers for checking if cgroup kmem > accounting is enabled: > > - mem_cgroup_kmem_disabled > - memcg_kmem_enabled > > mem_cgroup_kmem_disabled is a simple helper that returns true > if cgroup.memory=nokmem is specified, otherwise returns false. > > memcg_kmem_enabled is a bit different, it returns true if > cgroup.memory=nokmem is not specified and there was at least one > non-root memory control enabled cgroup ever created. This help improve > performance when kmem accounting was not actually activated. And it's > optimized with static branch. > > The usage of mem_cgroup_kmem_disabled is for sub-systems that need to > preallocate data for kmem accounting since they could be initialized > before kmem accounting is activated. But count_objcg_event doesn't > need that, so using memcg_kmem_enabled is better here. > > Signed-off-by: Kairui Song Acked-by: Shakeel Butt