From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B8E5D606A31A for ; Thu, 29 Oct 2026 00:56:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Kq24YAtb Received: by kanga.kvack.org (Postfix) id D03F86B05B2; Wed, 28 Oct 2026 20:56:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CB4666B05B4; Wed, 28 Oct 2026 20:56:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BC9C66B05B5; Wed, 28 Oct 2026 20:56:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 9B5286B05B2 for ; Wed, 28 Oct 2026 20:56:35 -0400 (EDT) Received: from smtpin30.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id A23971A015F for ; Thu, 29 Oct 2026 00:55:50 +0000 (UTC) X-FDA: 85373846460.30.2CC301A Received: from mta0.migadu.com (out-228.mta0.migadu.com [91.218.175.228]) by imf21.hostedemail.com (Postfix) with ESMTP id 290671C0004 for ; Thu, 29 Oct 2026 00:55:46 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=Kq24YAtb; spf=pass (imf21.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.228 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793235349; b=hvtyQ2ThEQ1dS0XsPkVht2tpaq97gaNsSX82TOO0/I+G2RZ+DVf+rYFQDNcNAsJVhzA9KP tqznlS+Gl0S8lPPhtebQL4/8kK4CTyqBYZZz9Q71VLUPaoOQLJYZj5i2JZw3vtQZJZNrUJ 8ya+iJOqcJq0Qr3/hrCvoVlelsdswMs= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=Kq24YAtb; spf=pass (imf21.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.228 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793235349; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=fFzYuQaJCauylA1fGRQBnIg3JJop64i3OCtTEnPOz/Y=; b=IDamZpAq1mjVq51YNY9TFkYguVAz2n+QaHsRlk4DWYiNavKTdstm9nVN1SAZ9Ga29aszCx 7Ubd4MF/5doBHHTIS3C8sAsZU28C9YDSB0HzuOqE5VV98/4t7jZLavvthJEJSwmRkmfhBZ JRDa0FSjJntA5T9dr55BMPlGkqB34C8= X-Envelope-To: linux-mm@kvack.org DKIM-Signature: a=rsa-sha256; bh=yT3k3zYkwm+Ajt3rhJuC2pHkaVqR6QAMaSTFBMTEmxg=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793235345; v=1; x=1793840145; b=Kq24YAtbCnV/0p22oZCli0sPgTnpcN2bx8viUurrFAO9WCJaJp2aR7NIDOF4/Yw8EI4GLAaI pCTGfY/E/DPwZccPDtTVLexxHabyV0MFo7aEytvqGvktbi/HyfFYatgngZvX7+6lvTWflRGdixw Hwd8HjwFZxHiE3BoVCtNv8dg= X-Envelope-To: linux-mm@kvack.org Received: by smtp.migadu.com with ESMTPS id 1fc603a9cbf2cb33; Thu, 29 Oct 2026 00:55:33 +0000 X-Mizu-Trace-ID: 1fc603a9cbf2cb33 X-Migadu-Flow: FLOW_OUT Date: Wed, 28 Oct 2026 17:55:31 -0700 From: Shakeel Butt To: Kuniyuki Iwashima Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Kuniyuki Iwashima , linux-mm@kvack.org, cgroups@vger.kernel.org Subject: Re: [PATCH v2 3/6] memcg: Annotate slow paths in consume_stock() and refill_stock(). Message-ID: References: <20261028185034.3607746-1-kuniyu@google.com> <20261028185034.3607746-4-kuniyu@google.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261028185034.3607746-4-kuniyu@google.com> X-Rspam-User: X-Rspamd-Queue-Id: 290671C0004 X-Stat-Signature: xtjqmt9gqi1ih1bo74zkndtaai71w3jt X-Rspamd-Server: rspam01 X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-HE-Tag: 1793235346-423380 X-HE-Meta: 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 TDTynv3p LMgA4QO1HHzopoZlZapj0gPvBbuDeJgTlmxEe79wOEzqRoUPO2EE/ti+sNXI0sNCRM26UzO4g07gasxwqc5Ah4D2DK9DZ7MqFW7xjA3P8cNTEYF3NwuKIcKyzk9nqGdL9FaQpQ+GhIf4bhTQshBiML01ogdyQDpqBJzrNRopk6jUvx9rNLiQjPvdTQRSlt71k2mewhoQ4ElbL+KM1zVMjzl7lyuDjPdHKN0bKUsA2oXeMNrixENlswdF+CO3U/pGWW2hJjTAy+ke6wiwU8PU3gGOo1Yw+MgtSoKxwFRCuLRVa2cMzPz7cM1zM7mzG2Voh5dux Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Wed, Oct 28, 2026 at 06:50:15PM +0000, Kuniyuki Iwashima wrote: > In consume_stock() and refill_stock(), each per-CPU stock slot > holds up to MEMCG_STOCK_HIGH (64) pages, so depleting a slot in > consume_stock() (!stock_pages) or trimming a slot in refill_stock() > (stock_pages > MEMCG_STOCK_HIGH) happens at most once per batch. > > Similarly, requests larger than MEMCG_CHARGE_BATCH, local_trylock() > failure, and insufficient cached pages (stock_pages < nr_pages) > are all slow paths. > > Without unlikely() annotations (when building without FDO, or > when an FDO profile does not cover a caller), the compiler treats > these branches as likely and inlines css_put() in consume_stock() > and memcg_uncharge() in refill_stock() right into the middle of > the hot path. Please state the compiler along with its version here. I didn't see this behavior on gcc 14.