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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83DBDC433EF for ; Tue, 17 May 2022 03:54:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 012108D000E; Mon, 16 May 2022 23:54:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F04BD8D0003; Mon, 16 May 2022 23:54:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF28D8D000E; Mon, 16 May 2022 23:54:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id D18058D0003 for ; Mon, 16 May 2022 23:54:40 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 06E9860905 for ; Tue, 17 May 2022 03:54:40 +0000 (UTC) X-FDA: 79473868320.05.93FC6AD Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id 81E4A200C1 for ; Tue, 17 May 2022 03:54:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Jej/zNlHp42fGBciz21lgfdwP2bYx92R3jqDU7lJwVE=; b=W2KvdG7RfjLdXNIFYkZIwx/L6b Fm2U74FWqtNH+OJgDlLx9d1KHsLN867E91OX8LoJVgveHLgCkTm7Fi2M/WTi7h7VY2Bixqzpaak8u QeikjgScoYhxNzplj+sD/X5Il7VgyNV7ugN09Lue1oMbdTc592mR1VnZzu7YpZF3myCtp+ppBCxCJ nUhKIaPMPnYhgsUL92ibbsk452jVfiOctJpOq+JjnowXObG6idBJ2dpV037JmWMcNuLX45SC+koje Hy4ZUhvKe0WqeD06xogBXG405qM/ARS5i3f22wJX4DetsjRyEPyIXTY1UKGxNi1HNX52YafY73G10 xYv/jJkA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nqoHx-00AVOS-GY; Tue, 17 May 2022 03:54:25 +0000 Date: Tue, 17 May 2022 04:54:25 +0100 From: Matthew Wilcox To: Vasily Averin Cc: Shakeel Butt , Roman Gushchin , Vlastimil Babka , Andrew Morton , Joonsoo Kim , David Rientjes , Pekka Enberg , Christoph Lameter , kernel@openvz.org, Linux MM , LKML , Michal Hocko Subject: Re: [PATCH] tracing: add ACCOUNT flag for allocations from marked slab caches Message-ID: References: <1fd21e25-b095-e055-fc2e-abda640a0575@openvz.org> <0aaf7b6d-6ed7-45ca-873e-394718f73c9a@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0aaf7b6d-6ed7-45ca-873e-394718f73c9a@openvz.org> X-Stat-Signature: zc74dnhuo9ad4snfi8ixzrziadh5jixz Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=W2KvdG7R; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 81E4A200C1 X-HE-Tag: 1652759657-156652 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, May 17, 2022 at 06:32:28AM +0300, Vasily Averin wrote: > > Should this 'if' be unlikely() or should we trace cachep->flags > > explicitly to avoid this branch altogether? > > In general output of cachep->flags can be useful, but at the moment > I am only interested in SLAB_ACCOUNT flag and in any case I would > prefer to translate it to GFP_ACCOUNT. > So I'm going to use unlikely() in v2 patch version. It's still going to be an extra test, and networking is extremely sensitive to extra instructions if tracing is compiled out. Passing in 'cachep' to the trace call looked like the best suggestion to me.