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 DEEE3C433F5 for ; Wed, 11 May 2022 06:24:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239936AbiEKGYw (ORCPT ); Wed, 11 May 2022 02:24:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230315AbiEKGYr (ORCPT ); Wed, 11 May 2022 02:24:47 -0400 Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15AF521333E for ; Tue, 10 May 2022 23:24:45 -0700 (PDT) Received: by mail-pf1-x436.google.com with SMTP id v11so1131328pff.6 for ; Tue, 10 May 2022 23:24:45 -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=4zqtIBImcyHLL9Tc/oW4yDkc5aMRTyCtWMqUHcmloj0=; b=HycIQXNS2m9V3MJ/RxfFqSQ1dNGbPq2hsqXt3N+/5/4n1GxevoeG9C0LQod72HP6Rs da2JXtDaTr2kiEI9cqaSS4ctWsu7D8PFy7LCTt0HOgxbto38vsoe5Xu/eIOkQTp/daXi Q7ExLiKfo2obFFw7Dd5m0nhlcSQ+p4vAF8Ne6PNKpyjydvtd/8xwK6HLTpE1pGM17PQh SE6+eyq1i74pYJiHbSAQUOd4vcH7Illk6eGPcS1dHoWmjqRvywIzBguSe7T+vuM7PS+W yjB0NasFpFQR1mBZ5Dv8qWozKSMXAJs1aAztvPaUta34bZkKDC2Rk2wgmlwIz8TqH7WY uuqw== 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=4zqtIBImcyHLL9Tc/oW4yDkc5aMRTyCtWMqUHcmloj0=; b=2KBHKATUpCq+QdHvSWnuJyCGL1wVdUiFDYGYFfDtWsfsAB4w4tF21VvocePKiR00L4 PMYRvFkONU8IehINlK+NgeBhFu0wQaxVO0vw1fqtFgiwEyg1GzRW7lhMtkT5qJ+Wp+p9 fmN9wN0Enf0qoXNRt83V3Csp1Mkj+GvpLw54UQq7mGZXAaM8l1YgncRPJFSmGIcWSeDR 7/oaZ/aJVqfI6X2Btg9dQhKZkh7LJ7QWrTI+Kc5JdEdfND1/FgPcYp+/ddjFi3EBMc5T iXjauFEUR72YzXmH3l1by1tLK92NNW2LM+5BYVyzaEbMMHNlWBeGFcgVzwIhXXUF0fg7 Cv3w== X-Gm-Message-State: AOAM532UKf5r7QaexzjnjkMnXq6uVteVt8w9i0BVgQA/lYtfEvAmqTX+ rM8OiEY5XulkmGuoJaIgCdoNqA== X-Google-Smtp-Source: ABdhPJx9zGROrNwYSZvhPjwrVU3mGUauq8w0wmlDTj7rDU82fX0V8EALKUq5p8NE8ZuKZScEgsv6gQ== X-Received: by 2002:a05:6a00:996:b0:505:b6d2:abc8 with SMTP id u22-20020a056a00099600b00505b6d2abc8mr23981495pfg.11.1652250285267; Tue, 10 May 2022 23:24:45 -0700 (PDT) Received: from [10.254.203.126] ([139.177.225.242]) by smtp.gmail.com with ESMTPSA id y65-20020a638a44000000b003c1ee2c4242sm822832pgd.33.2022.05.10.23.24.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 10 May 2022 23:24:44 -0700 (PDT) Message-ID: Date: Wed, 11 May 2022 14:24:39 +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 v2 1/2] mm: fix missing handler for __GFP_NOWARN Content-Language: en-US To: akpm@linux-foundation.org, jirislaby@kernel.org, akinobu.mita@gmail.com, vbabka@suse.cz, gregkh@linuxfoundation.org, rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20220511061951.1114-1-zhengqi.arch@bytedance.com> From: Qi Zheng In-Reply-To: <20220511061951.1114-1-zhengqi.arch@bytedance.com> 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 2:19 PM, 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. > > But for some warnings that report usage problems, we don't deal with > them. If such warnings are printed, then we should fix the usage > problems. Such as the following case: > > WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); > > Signed-off-by: Qi Zheng > --- Changelog in v1 -> v2: - add comment to WARN_ON_ONCE_GFP - handle __alloc_contig_migrate_range() case - do not deal with: WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); > include/linux/fault-inject.h | 2 ++ > lib/fault-inject.c | 3 +++ > mm/failslab.c | 3 +++ > mm/internal.h | 15 +++++++++++++++ > mm/page_alloc.c | 18 ++++++++++-------- > 5 files changed, 33 insertions(+), 8 deletions(-) > > diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h > index 2d04f6448cde..9f6e25467844 100644 > --- a/include/linux/fault-inject.h > +++ b/include/linux/fault-inject.h > @@ -20,6 +20,7 @@ struct fault_attr { > atomic_t space; > unsigned long verbose; > bool task_filter; > + bool no_warn; > unsigned long stacktrace_depth; > unsigned long require_start; > unsigned long require_end; > @@ -39,6 +40,7 @@ struct fault_attr { > .ratelimit_state = RATELIMIT_STATE_INIT_DISABLED, \ > .verbose = 2, \ > .dname = NULL, \ > + .no_warn = false, \ > } > > #define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER > diff --git a/lib/fault-inject.c b/lib/fault-inject.c > index ce12621b4275..423784d9c058 100644 > --- a/lib/fault-inject.c > +++ b/lib/fault-inject.c > @@ -41,6 +41,9 @@ EXPORT_SYMBOL_GPL(setup_fault_attr); > > static void fail_dump(struct fault_attr *attr) > { > + if (attr->no_warn) > + return; > + > if (attr->verbose > 0 && __ratelimit(&attr->ratelimit_state)) { > printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure.\n" > "name %pd, interval %lu, probability %lu, " > diff --git a/mm/failslab.c b/mm/failslab.c > index f92fed91ac23..58df9789f1d2 100644 > --- a/mm/failslab.c > +++ b/mm/failslab.c > @@ -30,6 +30,9 @@ bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags) > if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB)) > return false; > > + if (gfpflags & __GFP_NOWARN) > + failslab.attr.no_warn = true; > + > return should_fail(&failslab.attr, s->object_size); > } > > diff --git a/mm/internal.h b/mm/internal.h > index e3e50af20706..34fdedb9986f 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -35,6 +35,21 @@ struct folio_batch; > /* Do not use these with a slab allocator */ > #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK) > > +/* > + * Different from WARN_ON_ONCE(), no warning will be issued > + * when we specify __GFP_NOWARN. > + */ > +#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); \ > +}) > + > void page_writeback_init(void); > > static inline void *folio_raw_mapping(struct folio *folio) > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 65f892af1d4f..f9f329403d76 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3789,6 +3789,9 @@ static bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) > (gfp_mask & __GFP_DIRECT_RECLAIM)) > return false; > > + if (gfp_mask & __GFP_NOWARN) > + fail_page_alloc.attr.no_warn = true; > + > return should_fail(&fail_page_alloc.attr, 1 << order); > } > > @@ -4337,7 +4340,8 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, > */ > > /* Exhausted what can be done so it's blame time */ > - if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) { > + if (out_of_memory(&oc) || > + WARN_ON_ONCE_GFP(gfp_mask & __GFP_NOFAIL, gfp_mask)) { > *did_some_progress = 1; > > /* > @@ -5103,7 +5107,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, > * All existing users of the __GFP_NOFAIL are blockable, so warn > * of any new users that actually require GFP_NOWAIT > */ > - if (WARN_ON_ONCE(!can_direct_reclaim)) > + if (WARN_ON_ONCE_GFP(!can_direct_reclaim, gfp_mask)) > goto fail; > > /* > @@ -5111,7 +5115,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, > * because we cannot reclaim anything and only can loop waiting > * for somebody to do a work for us > */ > - WARN_ON_ONCE(current->flags & PF_MEMALLOC); > + WARN_ON_ONCE_GFP(current->flags & PF_MEMALLOC, gfp_mask); > > /* > * non failing costly orders are a hard requirement which we > @@ -5119,7 +5123,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, > * so that we can identify them and convert them to something > * else. > */ > - WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER); > + WARN_ON_ONCE_GFP(order > PAGE_ALLOC_COSTLY_ORDER, gfp_mask); > > /* > * Help non-failing allocations by giving them access to memory > @@ -5365,10 +5369,8 @@ struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid, > * There are several places where we assume that the order value is sane > * so bail out early if the request is out of bound. > */ > - if (unlikely(order >= MAX_ORDER)) { > - WARN_ON_ONCE(!(gfp & __GFP_NOWARN)); > + if (WARN_ON_ONCE_GFP(order >= MAX_ORDER, gfp)) > return NULL; > - } > > gfp &= gfp_allowed_mask; > /* > @@ -9020,7 +9022,7 @@ int __alloc_contig_migrate_range(struct compact_control *cc, > > lru_cache_enable(); > if (ret < 0) { > - if (ret == -EBUSY) > + if (!(cc->gfp_mask & __GFP_NOWARN) && ret == -EBUSY) > alloc_contig_dump_pages(&cc->migratepages); > putback_movable_pages(&cc->migratepages); > return ret; -- Thanks, Qi