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=-24.0 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 4E2E8C07E9C for ; Fri, 9 Jul 2021 15:18:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34F9061378 for ; Fri, 9 Jul 2021 15:18:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232383AbhGIPVd (ORCPT ); Fri, 9 Jul 2021 11:21:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232335AbhGIPVc (ORCPT ); Fri, 9 Jul 2021 11:21:32 -0400 Received: from mail-yb1-xb33.google.com (mail-yb1-xb33.google.com [IPv6:2607:f8b0:4864:20::b33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70EF9C0613DD for ; Fri, 9 Jul 2021 08:18:48 -0700 (PDT) Received: by mail-yb1-xb33.google.com with SMTP id v189so6716567ybg.3 for ; Fri, 09 Jul 2021 08:18:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=hGX3UGEwXfFwKKdhbKxdN5Z9a9eTLdUcU8IFnRtBKXI=; b=dxLikpQTw+JGI68eVGXPE6+Vh6CNs2aa72+3GaFp/nhZH3pkxKvuJ4GDphfvTwANQh DwW5jmyPQNxQp+Gyg+r7oZaSKpbXMTnjJ9thXEB5FircFSbyu2WlopPeIjGFD4KnbEJ3 bYzsdtMFPHBOdJiiJ2OcgObtZ/BHPgIcxPnlYvdZIjtQpa1ltOWVphSG/gUJ6w+ODLMF 9RBzHBKRDJXEzH9lBmrhfqHDt7i9UzkjLi0ltOMOhrvm+TUFqvi/v0HjDEIMYHVm2mga 7RvC6esBxwFX8ldoMQR+kadRcZVFoEXd48ZRjWo3iW1tQHu+xqXdgTmwcUhQXbR+S8So 4Srw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=hGX3UGEwXfFwKKdhbKxdN5Z9a9eTLdUcU8IFnRtBKXI=; b=DizHXpnsN9LdKlC1Gn2TVOwbIxYEy7teNANjMcy7XGOGI64LTPBMaK45alqRSJb+Cc UwHs/PoyHKu4C6+PQbZk7lc9Rr03v9ELEz24IitpBvEyyags2WL7vbryZU7TeQNeaP2k s4r0ePPp4jOQPVRoJ6gm7wdS0NVj5LBlRKRnTgVMPDK4uR4RGnemc8enLPm/84s+0GHw l61KFf3lbc2iKh5J1+aabZr+c2TLZQ2zjR354/ZvD+YqJrtV2fqqc5SeVQTnEfJ8nrqZ Ueuow1bkb5a1eXr/t0RnJKN+bqPZas4IU22fmBDW2lMQN0MYwS5VyUPp4rA0H03vQ1AK PTIg== X-Gm-Message-State: AOAM530FBAw7OJE6EwBQGHB471zoRtxDJRwK03NiVMM9t6RbHKY0Aw9t z8AhhI1IurJI272HZULkUIsFtwafEmSFjuRq9O8M5A== X-Google-Smtp-Source: ABdhPJwy1KyUlSJdT8D6JvKzadspjS0MDYDuIZ/heFt7araixWEYiSoXGf5pfMlKnIsH+B/BkTG08YBlEtc8qa7V6Ts= X-Received: by 2002:a25:ba08:: with SMTP id t8mr47499494ybg.111.1625843927371; Fri, 09 Jul 2021 08:18:47 -0700 (PDT) MIME-Version: 1.0 References: <20210709000509.2618345-1-surenb@google.com> <20210709000509.2618345-3-surenb@google.com> In-Reply-To: From: Suren Baghdasaryan Date: Fri, 9 Jul 2021 08:18:36 -0700 Message-ID: Subject: Re: [PATCH 2/3] mm, memcg: inline mem_cgroup_{charge/uncharge} to improve disabled memcg config To: Johannes Weiner Cc: Tejun Heo , Michal Hocko , vdavydov.dev@gmail.com, Andrew Morton , Shakeel Butt , Roman Gushchin , songmuchun@bytedance.com, Yang Shi , alexs@kernel.org, alexander.h.duyck@linux.intel.com, richard.weiyang@gmail.com, Vlastimil Babka , Jens Axboe , Joonsoo Kim , David Hildenbrand , Matthew Wilcox , apopple@nvidia.com, Minchan Kim , linmiaohe@huawei.com, LKML , cgroups mailinglist , linux-mm , kernel-team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 9, 2021 at 7:48 AM Johannes Weiner wrote: > > On Thu, Jul 08, 2021 at 05:05:08PM -0700, Suren Baghdasaryan wrote: > > Inline mem_cgroup_{charge/uncharge} and mem_cgroup_uncharge_list functions > > functions to perform mem_cgroup_disabled static key check inline before > > calling the main body of the function. This minimizes the memcg overhead > > in the pagefault and exit_mmap paths when memcgs are disabled using > > cgroup_disable=memory command-line option. > > This change results in ~0.4% overhead reduction when running PFT test > > comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory} > > configurationon on an 8-core ARM64 Android device. > > > > Signed-off-by: Suren Baghdasaryan > > Sounds reasonable to me as well. One comment: > > > @@ -693,13 +693,59 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg) > > page_counter_read(&memcg->memory); > > } > > > > -int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask); > > +struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm); > > + > > +int __mem_cgroup_charge(struct page *page, struct mem_cgroup *memcg, > > + gfp_t gfp); > > +/** > > + * mem_cgroup_charge - charge a newly allocated page to a cgroup > > + * @page: page to charge > > + * @mm: mm context of the victim > > + * @gfp_mask: reclaim mode > > + * > > + * Try to charge @page to the memcg that @mm belongs to, reclaiming > > + * pages according to @gfp_mask if necessary. if @mm is NULL, try to > > + * charge to the active memcg. > > + * > > + * Do not use this for pages allocated for swapin. > > + * > > + * Returns 0 on success. Otherwise, an error code is returned. > > + */ > > +static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm, > > + gfp_t gfp_mask) > > +{ > > + struct mem_cgroup *memcg; > > + int ret; > > + > > + if (mem_cgroup_disabled()) > > + return 0; > > + > > + memcg = get_mem_cgroup_from_mm(mm); > > + ret = __mem_cgroup_charge(page, memcg, gfp_mask); > > + css_put(&memcg->css); > > + > > + return ret; > > Why not do > > int __mem_cgroup_charge(struct page *page, struct mm_struct *mm, > gfp_t gfp_mask); > > static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm, > gfp_t gfp_mask) > { > if (mem_cgroup_disabled()) > return 0; > > return __mem_cgroup_charge(page, memcg, gfp_mask); > } > > like in the other cases as well? > > That would avoid inlining two separate function calls into all the > callsites... > > There is an (internal) __mem_cgroup_charge() already, but you can > rename it charge_memcg(). Sounds good. I'll post an updated version with your suggestion. Thanks for the review, Johannes! >