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 2BAF5C4167D for ; Thu, 9 Nov 2023 17:50:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9846428000A; Thu, 9 Nov 2023 12:50:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 93464280009; Thu, 9 Nov 2023 12:50:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7D60A28000A; Thu, 9 Nov 2023 12:50:00 -0500 (EST) 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 6A98F280009 for ; Thu, 9 Nov 2023 12:50:00 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 432DFA0474 for ; Thu, 9 Nov 2023 17:50:00 +0000 (UTC) X-FDA: 81439154160.07.8E20F72 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf09.hostedemail.com (Postfix) with ESMTP id 3A9CC140003 for ; Thu, 9 Nov 2023 17:49:56 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=xYTL38kU; dmarc=none; spf=pass (imf09.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1699552197; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/KJMc3DthLUNpSacjtAoENVQ3TQN7B/oamk6ya8t2oQ=; b=xxzkHT51TYTHn8Hhrqy1qitxPh0MOiOdv7oz3iCSztKOfgWj/Qs2H3iPgdW2QfnU02vVtK +WofSFutFxD4GXm4V2TIDX1gKUytTNyeWv/8O0BqL6HB40koF+t+1PFcVgdQ8j7Ci5qs8E ckFCVqOfnUDH5kicSZFtFNy7woyopg0= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=xYTL38kU; dmarc=none; spf=pass (imf09.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1699552197; a=rsa-sha256; cv=none; b=q/sQTHCcKeXcYSiYx4zmZObtt+OQdhSWRTkcmtlLX8y/i0tXkDM9oNxMokmCFppi+ihcwp ZeIO13UU1vNaQAuCHXTAcA65JWeMYNzD/TvuLJTJVpScyFu3dfrIioue7SJNNc6rRVGeXi perwf+hfXklSunAVkyUMcTk2BcDtKSw= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 9589FB82171; Thu, 9 Nov 2023 17:49:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF245C433C8; Thu, 9 Nov 2023 17:49:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1699552195; bh=lZIcEOpqBq7V6sLEF4bOlqA/HFLe7+H0GXK/xFyC9AM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=xYTL38kU6Vve0VHhIA7PDkbEO6ODJS5kTg/g66xnrnAWnQ6fv2bvOLu68oKa36UG3 kLTKkhys5fV65SoLxC7MKrTU2QsIxGKzV79mqNn2AYrcCPWF4lVjNe1UQB08xSBqJb hTFFSzDJwriZyA8r19DYDpNEpgRb9FlJYZY9q4sM= Date: Thu, 9 Nov 2023 09:49:54 -0800 From: Andrew Morton To: Zhiguo Jiang Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner , opensource.kernel@vivo.com Subject: Re: [PATCH v2 1/1] mm: ALLOC_HIGHATOMIC flag allocation issue Message-Id: <20231109094954.dd4b2a5b1f5dfcc9a721edba@linux-foundation.org> In-Reply-To: <20231109073133.792-2-justinjiang@vivo.com> References: <20231109073133.792-1-justinjiang@vivo.com> <20231109073133.792-2-justinjiang@vivo.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 3A9CC140003 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: b7tr6xd4shq75zxqqqxydgycyiworu6c X-HE-Tag: 1699552196-183439 X-HE-Meta: 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 xGuqqq6+ Fy6aV8g4sWiY//WHhtcFC9gbuXuuKmL1c661iS2NaFsktrYmFYQMqUO4XL/1e/pA3geqLIZN4NE6f3LiyMYXWgojJTtqYp2KBsOYyvPFz/R51FnIfV9dxik+Nz54mLIr7Nsi2IOx0BFS/6KXf8lWnI1HH2n5TYfAia0IjJkn/SDJR47VZCgsDba6O1FZkZBVemWMTB+Hs/sqPokK2AY1Q/hWWm6+1Qjl7md+5Lvd64m+lpyG4i1YFkwAdyf1Zazh8XOrEkHJy00d875ZA+N0RqHs6fT+k64Uw4Fys5CTLDIvapYy394aIduSTywFh4naXjhEP45OxtmUK8x0= 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 Thu, 9 Nov 2023 15:31:33 +0800 Zhiguo Jiang wrote: > Add a new bool* argument to pass return flag instead of *alloc_flags > and add the related comments. Please retain (and update) the changelog with each version of a patch. For reviewers (please), here's the v1 changelog: : In case of alloc_flags contain ALLOC_HIGHATOMIC and alloc order : is order1/2/3/10 in rmqueue(), if pages are alloced successfully : from pcplist cache, and move a free pageblock from the alloced : migratetype freelist to MIGRATE_HIGHATOMIC freelist, rather than : alloc from MIGRATE_HIGHATOMIC freelist firstly, so this will result : in an increasing number of pages on the MIGRATE_HIGHATOMIC freelist, : pages in other migratetype freelist are reduced and more likely to : allocation failure. : : Currently the sequence of ALLOC_HIGHATOMIC allocation is: : pcplist cache --> buddy (batch >> order) allocation migratetype : freelist --> buddy MIGRATE_HIGHATOMIC freelist --> buddy allocation : migratetype freelist. : : Due to the fact that requesting pages from the pcplist cache is faster : than buddy, the sequence of modifying the ALLOC_HIGHATOMIC allocation is: : pcplist --> buddy MIGRATE_HIGHATOMIC freelist --> buddy allocation : migrate freelist. : : This patch can solve the allocation failure of the Non-ALLOC_HIGHATOMIC : alloc_flag due to excessive pages reservations in MIGRATE_HIGHATOMIC : freelists. > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -905,7 +905,6 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone, > #endif > #define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */ > #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */ > -#define ALLOC_PCPLIST 0x1000 /* Allocations from pcplist */ > > /* Flags that allow allocations below the min watermark. */ > #define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM) > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 67cec88164b1..3c84c3e3eeb0 100755 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2854,6 +2854,11 @@ struct page *__rmqueue_pcplist(struct zone *zone, unsigned int order, > int batch = nr_pcp_alloc(pcp, zone, order); > int alloced; > > + /* > + * If pcplist is empty and alloc_flags is with ALLOC_HIGHATOMIC, > + * it should alloc from buddy highatomic migrate freelist firstly > + * to ensure quick and successful allocation. > + */ > if (alloc_flags & ALLOC_HIGHATOMIC) > goto out; > > @@ -2925,8 +2930,8 @@ __no_sanitize_memory > static inline > struct page *rmqueue(struct zone *preferred_zone, > struct zone *zone, unsigned int order, > - gfp_t gfp_flags, unsigned int *alloc_flags, > - int migratetype) > + gfp_t gfp_flags, unsigned int alloc_flags, > + int migratetype, bool *highatomc_allocation) > { > struct page *page; > > @@ -2938,19 +2943,33 @@ struct page *rmqueue(struct zone *preferred_zone, > > if (likely(pcp_allowed_order(order))) { > page = rmqueue_pcplist(preferred_zone, zone, order, > - migratetype, *alloc_flags); > - if (likely(page)) { > - *alloc_flags |= ALLOC_PCPLIST; > + migratetype, alloc_flags); > + if (likely(page)) > goto out; > - } > } > > - page = rmqueue_buddy(preferred_zone, zone, order, *alloc_flags, > + page = rmqueue_buddy(preferred_zone, zone, order, alloc_flags, > migratetype); > > + /* > + * The high-order atomic allocation pageblock reserved conditions: > + * > + * If the high-order atomic allocation page is alloced from pcplist, > + * the highatomic pageblock does not need to be reserved, which can > + * void to migrate an increasing number of pages into buddy > + * MIGRATE_HIGHATOMIC freelist and lead to an increasing risk of > + * allocation failure on other buddy migrate freelists. > + * > + * If the high-order atomic allocation page is alloced from buddy > + * highatomic migrate freelist, regardless of whether the allocation > + * is successful or not, the highatomic pageblock can try to be > + * reserved. > + */ > + if (unlikely(alloc_flags & ALLOC_HIGHATOMIC)) > + *highatomc_allocation = true; > out: > /* Separate test+clear to avoid unnecessary atomics */ > - if ((*alloc_flags & ALLOC_KSWAPD) && > + if ((alloc_flags & ALLOC_KSWAPD) && > unlikely(test_bit(ZONE_BOOSTED_WATERMARK, &zone->flags))) { > clear_bit(ZONE_BOOSTED_WATERMARK, &zone->flags); > wakeup_kswapd(zone, 0, 0, zone_idx(zone)); > @@ -3218,6 +3237,7 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, > struct pglist_data *last_pgdat = NULL; > bool last_pgdat_dirty_ok = false; > bool no_fallback; > + bool highatomc_allocation = false; > > retry: > /* > @@ -3349,7 +3369,7 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, > > try_this_zone: > page = rmqueue(ac->preferred_zoneref->zone, zone, order, > - gfp_mask, &alloc_flags, ac->migratetype); > + gfp_mask, alloc_flags, ac->migratetype, &highatomc_allocation); > if (page) { > prep_new_page(page, order, gfp_mask, alloc_flags); > > @@ -3357,8 +3377,7 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, > * If this is a high-order atomic allocation then check > * if the pageblock should be reserved for the future > */ > - if (unlikely(alloc_flags & ALLOC_HIGHATOMIC) && > - unlikely(!(alloc_flags & ALLOC_PCPLIST))) > + if (unlikely(highatomc_allocation)) > reserve_highatomic_pageblock(page, zone); > > return page; > -- > 2.39.0