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 8CAF2C433EF for ; Wed, 11 May 2022 02:20:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241050AbiEKCUB (ORCPT ); Tue, 10 May 2022 22:20:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241120AbiEKCT5 (ORCPT ); Tue, 10 May 2022 22:19:57 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 020A61F68F9 for ; Tue, 10 May 2022 19:19:55 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id 31so542908pgp.8 for ; Tue, 10 May 2022 19:19:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=aIcSWreA+W0fIvQF/lKPGeaT+AYkn45ShR5b36w2q9o=; b=5/Lld5QMG+BiecKOlFA0wMezCYTbJ4Q/Gr1IDeFcKOgwH72fHR/jtrHCNGGMByZica LNS+OwfFslOxBaD726ya9nFnMOyGhUZBx/gHhRrRs8LHcaVctkHJOnukBmNOADOQO0+Q 70dYgeXJ4F+cZ63RkvgS+xoV1jHAV5GCpiKIDz524T6jZfyKpEaXLlVVppELH0BwmFiu gEtI/8m0ldv/cso79j5SnOM6uZ3oy7YmlgAnC7mVCcM7jpqtjVaFuKQjpa5QD/MNV/YP KwD94fE0OA0ycX8EtoMtYCywvZX4w5sTdXxer+u6+FUVFTCi5WgJokQi5s9uq2OEk5A4 kdxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=aIcSWreA+W0fIvQF/lKPGeaT+AYkn45ShR5b36w2q9o=; b=KaNQfxDwa+b31k+do32LnYjqOqs1KvcI2vUicPkU68pZnBxTKAJLgnaaXq8OGu2Rnk bVUWv4a0rdR/rYpMnM2XRlvLb1KvXJJ63DNf3ZamedKCDlbeLzQGh/bf2lCHsj64QKqR 9wZcGcFxBsz0mvAmpPKe7pNSjgryn4h0VW3k7Wq35Ict0ifv+nVuNm7g3tdcorn2Pp6Y 3z9jZXrLRki6zvgBJc6Wh2AtLP9rQv5vrSodEfzmKj0WZ9J6de6GdSzmmHq4dbHSFYKn PiuG1TDLz8c7LaOyGfWasO2yoiBJwUG1s4NYLLgEQ43/r6HNbEMGWToilKl+e/U5/fHf AEBg== X-Gm-Message-State: AOAM5306V+Lozh8tTw6AJJpaEY4/xlbk+GHPRkYQNBjzoZdlPDPcoIC8 w2ZI70RvVf0PjMoWJRvJCi+WzQ== X-Google-Smtp-Source: ABdhPJzsT4kywaSzyEnClAPCSvzS5a9FdNsQR+tCDLD/YGZINPYPEdTQS9hI6/siAiDs/tS2I1v38A== X-Received: by 2002:a63:197:0:b0:3aa:9c7a:b269 with SMTP id 145-20020a630197000000b003aa9c7ab269mr18813125pgb.158.1652235594538; Tue, 10 May 2022 19:19:54 -0700 (PDT) Received: from [10.254.203.126] ([139.177.225.242]) by smtp.gmail.com with ESMTPSA id a20-20020a63e414000000b003c14af50617sm407288pgi.47.2022.05.10.19.19.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 10 May 2022 19:19:54 -0700 (PDT) Message-ID: Date: Wed, 11 May 2022 10:19:48 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH 1/2] mm: fix missing handler for __GFP_NOWARN Content-Language: en-US To: Andrew Morton Cc: akinobu.mita@gmail.com, vbabka@suse.cz, gregkh@linuxfoundation.org, jirislaby@kernel.org, rostedt@goodmis.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20220510113809.80626-1-zhengqi.arch@bytedance.com> <20220510115922.350a496ca8b91686c1758282@linux-foundation.org> From: Qi Zheng In-Reply-To: <20220510115922.350a496ca8b91686c1758282@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/5/11 2:59 AM, Andrew Morton wrote: > On Tue, 10 May 2022 19:38:08 +0800 Qi Zheng wrote: > >> We expect no warnings to be issued when we specify __GFP_NOWARN, but >> currently in paths like alloc_pages() and kmalloc(), there are still >> some warnings printed, fix it. > > Looks sane to me. > >> --- a/mm/internal.h >> +++ b/mm/internal.h >> @@ -35,6 +35,17 @@ struct folio_batch; >> /* Do not use these with a slab allocator */ >> #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) >> >> +#define WARN_ON_ONCE_GFP(cond, gfp) ({ \ >> + static bool __section(".data.once") __warned; \ >> + int __ret_warn_once = !!(cond); \ >> + \ >> + if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \ >> + __warned = true; \ >> + WARN_ON(1); \ >> + } \ >> + unlikely(__ret_warn_once); \ >> +}) > > I don't think WARN_ON_ONCE_GFP is a good name for this. But > WARN_ON_ONCE_IF_NOT_GFP_NOWARN is too long :( > > WARN_ON_ONCE_NOWARN might be better. No strong opinion here, really. I've thought about WARN_ON_ONCE_NOWARN, but I feel a little weird putting 'WARN' and 'NOWARN' together, how about WARN_ON_ONCE_IF_ALLOWED? > >> @@ -4902,8 +4906,8 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, >> * We also sanity check to catch abuse of atomic reserves being used by >> * callers that are not in atomic context. >> */ >> - if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) == >> - (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM))) >> + if (WARN_ON_ONCE_GFP((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) == >> + (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM), gfp_mask)) >> gfp_mask &= ~__GFP_ATOMIC; >> >> retry_cpuset: > > I dropped this hunk - Neil's "mm: discard __GFP_ATOMIC" > (https://lkml.kernel.org/r/163712397076.13692.4727608274002939094@noble.neil.brown.name) > deleted this code. > This series is based on v5.18-rc5, I will rebase it to the latest next branch and check if there are any missing WARN_ON_ONCEs that are not being handled. Thanks, Qi -- Thanks, Qi