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 F360BC54E58 for ; Wed, 20 Mar 2024 18:33:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 49C236B0093; Wed, 20 Mar 2024 14:33:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 44C606B0096; Wed, 20 Mar 2024 14:33:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2ED136B0098; Wed, 20 Mar 2024 14:33:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 1BAB96B0093 for ; Wed, 20 Mar 2024 14:33:02 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id AF95D1C089F for ; Wed, 20 Mar 2024 18:33:01 +0000 (UTC) X-FDA: 81918264162.02.5743185 Received: from mail-lj1-f177.google.com (mail-lj1-f177.google.com [209.85.208.177]) by imf26.hostedemail.com (Postfix) with ESMTP id B15D2140018 for ; Wed, 20 Mar 2024 18:32:59 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=linaro.org header.s=google header.b=DYXhDOTP; spf=pass (imf26.hostedemail.com: domain of dan.carpenter@linaro.org designates 209.85.208.177 as permitted sender) smtp.mailfrom=dan.carpenter@linaro.org; dmarc=pass (policy=none) header.from=linaro.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1710959579; 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=Ogqc9yIyd+winYNxhTRHIu60n7nx2qJvwGWXSoSBDRw=; b=nHatovEeJtaFzE9jSOUxIZkvRl1hZhzM7REQHMBIFjcmaCZH5fOp4gh9EJB4bBqsoJaB+v Vbdub++I59TViIE7QCUpROFCNIMZZJjZdrVHpPUHlhr5YRTe3dG2LWTdULjNIaF7BQ/Qzh CVcRulEarkcbkaLco4AZGHjw8Oh64VA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1710959579; a=rsa-sha256; cv=none; b=CsIbxx2kTunzAX9t0ko9mlg9hPZ2hQTUM8WXFv97r5IEG0I2qeecGXSPwiRFdgmwWe8BXg 1MWA75DhryoA+NeCyqHpcL+ICNSEfGZmwqe8x4LCDD3zc2KJbHa/kTTYUFndS4pvJ3w5Nc MzXFHSE6AnMF4q6glxn+lpI9gEMbWOQ= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=linaro.org header.s=google header.b=DYXhDOTP; spf=pass (imf26.hostedemail.com: domain of dan.carpenter@linaro.org designates 209.85.208.177 as permitted sender) smtp.mailfrom=dan.carpenter@linaro.org; dmarc=pass (policy=none) header.from=linaro.org Received: by mail-lj1-f177.google.com with SMTP id 38308e7fff4ca-2d46dd5f222so2382781fa.1 for ; Wed, 20 Mar 2024 11:32:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1710959578; x=1711564378; darn=kvack.org; 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=Ogqc9yIyd+winYNxhTRHIu60n7nx2qJvwGWXSoSBDRw=; b=DYXhDOTPv6M83Q+UbioIx0aJaSUuzgHKt2YApSw+U8nPBKMkEATuYzzDKytS49Xddv +MKeYk2uZSwZ+/RAfAOM+YMdsNngM6SBBR3PuO1BEDBqZypav1FQQt6YbwmojMSQ7gO1 TqKjtKc8fdvpF8eTxjynSRbaFJDIXUTq4dFtAPhg1t/93/sRF7BRM2P+cVnKrFt7nMy/ hKZZWNblAke9ZC/FHOAm6jBA8ny75vXWTCXFgs4zfN9QdisEfFe0YheGKsJi1+yQh0Gp jDhUgX7uiNNIzXGjeFFOnFk6WYBa1qA78c4qeVbNwoAqR3ivbDGOh5V4eFukZUol3qoF oRlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710959578; x=1711564378; 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=Ogqc9yIyd+winYNxhTRHIu60n7nx2qJvwGWXSoSBDRw=; b=cnm+53wYzz5dFQ3FJ36V1d8gX12sPyoP8JCxC+VXodYIKItfJNr1NRIIQUFx4hHsEx 8qWl5tjew/NwkjMrFH9+ZZv4n/73cloMMEgbMbWbADt0/UrsQfae1aF/lweXUa3xxL+l Y+NbAwISqQH8qLdFcy+IIbhk5dGQsHTj6VeepABcymmJLPiHNmtLiuGeINCf1XfJS1v9 w+S8hFwvS06cWDCR8GG76ENHyQiHNUaXvH+QJfmSMZ3JxUfGVLE4k5gbCMDPsOwPr1Rw /+appxLCNQ8cFSA+6xLj0rCfvbPSFX14hL/rDmXjvHXoxDI7P76Md6y9/7xY87PjRSGq L6lA== X-Forwarded-Encrypted: i=1; AJvYcCUnZTAaMoyEm/bWkltOFMduNz2XEhj6umYVfyDBkILypO6Qs9exWrBOuunPRchV36InUZ1A4ZDOoNaFISYyqPS4WEI= X-Gm-Message-State: AOJu0YwdWmLi0vB+QZpqm8WnFLyydZLp77gvyABRzztrqzKom4ni4Tr1 XrU7G/YJQ1E1S2inPpUOfPntql3Towx9l6g5HCLKElwquFc7au6w7L+I5Y6FLwg= X-Google-Smtp-Source: AGHT+IHKJ6K6y29axy/aP5DCgrp0Yz9RxQ+j9lvERuKx9mqFi9BKRR/lfn66qaKuBr5eBlZoJvqgew== X-Received: by 2002:a2e:8645:0:b0:2d4:51f4:dbee with SMTP id i5-20020a2e8645000000b002d451f4dbeemr12641554ljj.53.1710959577444; Wed, 20 Mar 2024 11:32:57 -0700 (PDT) Received: from localhost ([102.222.70.76]) by smtp.gmail.com with ESMTPSA id s10-20020a05600c45ca00b0041401eb021asm3000762wmo.24.2024.03.20.11.32.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Mar 2024 11:32:56 -0700 (PDT) Date: Wed, 20 Mar 2024 21:32:52 +0300 From: Dan Carpenter To: Vlastimil Babka Cc: NeilBrown , Kent Overstreet , Dave Chinner , Matthew Wilcox , Amir Goldstein , paulmck@kernel.org, lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, linux-fsdevel , Jan Kara Subject: Re: [Lsf-pc] [LSF/MM/BPF TOPIC] Reclamation interactions with RCU Message-ID: References: <170925937840.24797.2167230750547152404@noble.neil.brown.name> <170933687972.24797.18406852925615624495@noble.neil.brown.name> <170950594802.24797.17587526251920021411@noble.neil.brown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: B15D2140018 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: j9afdh5gqys3cx1w7wxo3ugohu45tm88 X-HE-Tag: 1710959579-504624 X-HE-Meta: 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 44tma+9G gzPamPLdXRIq4OeoIDi6dryX/kd3PxJfYyUwedMkGDa0mxH7jjiwGe1FzbxSW6AqkkWaz4xiHBb+jQkO8KTNYnaZTcjyUuhye4hfdmkBYl/0WsWXTwvX7hnbcKwoPFzNZRkUXu3kLO4My+bvkzDO7lC3oreRQdFedKDvUtr5KmJnuhdqis3pkkU4GZ8rfpm+Ro2zVVjU8qAhPJhuyjBOLBUGbv+RZ0Yj5ngQUOqDF2ydAmMzgsvGP9PSe0ftP1C49J0Qcq11YBE2VrpjqCCRoSfYt5dfNJMK/SQCLrpwEPrCom42vDTClbNxFCQ== 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: List-Subscribe: List-Unsubscribe: On Tue, Mar 12, 2024 at 03:46:32PM +0100, Vlastimil Babka wrote: > But if we change it to effectively mean GFP_NOFAIL (for non-costly > allocations), there should be a manageable number of places to change to a > variant that allows failure. What does that even mean if GFP_NOFAIL can fail for "costly" allocations? I thought GFP_NOFAIL couldn't fail at all... Unfortunately, it's common that when we can't decide on a sane limit for something people just say "let the user decide based on how much memory they have". I have added some integer overflow checks which allow the user to allocate up to UINT_MAX bytes so I know this code is out there. We can't just s/GFP_KERNEL/GFP_NOFAIL/. >From a static analysis perspective it would be nice if the callers explicitly marked which allocations can fail and which can't. regards, dan carpenter