From patchwork Tue Nov 29 15:17:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 13058713 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 795A7C4167B for ; Tue, 29 Nov 2022 15:18:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F278A6B007D; Tue, 29 Nov 2022 10:18:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EB8BF6B007E; Tue, 29 Nov 2022 10:18:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D51046B0080; Tue, 29 Nov 2022 10:18:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id C058E6B007D for ; Tue, 29 Nov 2022 10:18:19 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 655FAA07E1 for ; Tue, 29 Nov 2022 15:18:19 +0000 (UTC) X-FDA: 80186835918.17.11A0FB2 Received: from outbound-smtp43.blacknight.com (outbound-smtp43.blacknight.com [46.22.139.229]) by imf23.hostedemail.com (Postfix) with ESMTP id A1D58140004 for ; Tue, 29 Nov 2022 15:18:17 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp43.blacknight.com (Postfix) with ESMTPS id 5605919B1 for ; Tue, 29 Nov 2022 15:18:16 +0000 (GMT) Received: (qmail 6602 invoked from network); 29 Nov 2022 15:18:16 -0000 Received: from unknown (HELO morpheus.112glenside.lan) (mgorman@techsingularity.net@[84.203.198.246]) by 81.17.254.9 with ESMTPA; 29 Nov 2022 15:18:16 -0000 From: Mel Gorman To: Linux-MM Cc: Andrew Morton , Michal Hocko , NeilBrown , Thierry Reding , Matthew Wilcox , Vlastimil Babka , LKML , Mel Gorman Subject: [PATCH 6/6] mm: discard __GFP_ATOMIC Date: Tue, 29 Nov 2022 15:17:01 +0000 Message-Id: <20221129151701.23261-7-mgorman@techsingularity.net> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20221129151701.23261-1-mgorman@techsingularity.net> References: <20221129151701.23261-1-mgorman@techsingularity.net> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669735097; a=rsa-sha256; cv=none; b=kfjPZF8XSa9jsKUBjhdXc0kBZEWNKqdjfiB4JIXCNAW8x/DBo+54lla+TAgkhbhMydlkmH u0YaZm7T+N43g1F8ukenCQT7Dv0sALJ+TzRzOEm1FtzEv6w/N6eiuLEsonEPlTboALqQ6y ietpZlMScbDihjnF1uCa3i4R+n1Rgxo= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf23.hostedemail.com: domain of mgorman@techsingularity.net designates 46.22.139.229 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1669735097; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oON1Kd6q4vEqlE2We52TsIWsF3C1BheqHlfIrulUxbM=; b=jzTerEZsPwxb1G2MDZ8QpqAGJBL/yksQx9Bw7y5FPWwEyqnNqr+28RcY121ugTUB+m0EEf +7m15DvDs5K9InarXzpkf2kL9glznwichlGNUGHWFMlCsCJDLCn+vas7l5qZQwRx4X5Jf7 c7c4UKYVu5s0MyavZ5z+AtL35qIm4KY= X-Rspamd-Queue-Id: A1D58140004 Authentication-Results: imf23.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf23.hostedemail.com: domain of mgorman@techsingularity.net designates 46.22.139.229 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net X-Rspamd-Server: rspam12 X-Rspam-User: X-Stat-Signature: u45guqbnupj5695g6pcq6q34dgqdfimg X-HE-Tag: 1669735097-236000 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: From: NeilBrown __GFP_ATOMIC serves little purpose. Its main effect is to set ALLOC_HARDER which adds a few little boosts to increase the chance of an allocation succeeding, one of which is to lower the water-mark at which it will succeed. It is *always* paired with __GFP_HIGH which sets ALLOC_HIGH which also adjusts this watermark. It is probable that other users of __GFP_HIGH should benefit from the other little bonuses that __GFP_ATOMIC gets. __GFP_ATOMIC also gives a warning if used with __GFP_DIRECT_RECLAIM. There is little point to this. We already get a might_sleep() warning if __GFP_DIRECT_RECLAIM is set. __GFP_ATOMIC allows the "watermark_boost" to be side-stepped. It is probable that testing ALLOC_HARDER is a better fit here. __GFP_ATOMIC is used by tegra-smmu.c to check if the allocation might sleep. This should test __GFP_DIRECT_RECLAIM instead. This patch: - removes __GFP_ATOMIC - allows __GFP_HIGH allocations to ignore watermark boosting as well as GFP_ATOMIC requests. - makes other adjustments as suggested by the above. The net result is not change to GFP_ATOMIC allocations. Other allocations that use __GFP_HIGH will benefit from a few different extra privileges. This affects: xen, dm, md, ntfs3 the vermillion frame buffer hibernation ksm swap all of which likely produce more benefit than cost if these selected allocation are more likely to succeed quickly. [mgorman: Minor adjustments to rework on top of a series] Link: https://lkml.kernel.org/r/163712397076.13692.4727608274002939094@noble.neil.brown.name Signed-off-by: NeilBrown Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka --- Documentation/mm/balance.rst | 2 +- drivers/iommu/tegra-smmu.c | 4 ++-- include/linux/gfp_types.h | 12 ++++-------- include/trace/events/mmflags.h | 1 - lib/test_printf.c | 8 ++++---- mm/internal.h | 2 +- mm/page_alloc.c | 13 +++---------- tools/perf/builtin-kmem.c | 1 - 8 files changed, 15 insertions(+), 28 deletions(-) diff --git a/Documentation/mm/balance.rst b/Documentation/mm/balance.rst index 6a1fadf3e173..e38e9d83c1c7 100644 --- a/Documentation/mm/balance.rst +++ b/Documentation/mm/balance.rst @@ -6,7 +6,7 @@ Memory Balancing Started Jan 2000 by Kanoj Sarcar -Memory balancing is needed for !__GFP_ATOMIC and !__GFP_KSWAPD_RECLAIM as +Memory balancing is needed for !__GFP_HIGH and !__GFP_KSWAPD_RECLAIM as well as for non __GFP_IO allocations. The first reason why a caller may avoid reclaim is that the caller can not diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index 5b1af40221ec..af8d0e685260 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c @@ -671,12 +671,12 @@ static struct page *as_get_pde_page(struct tegra_smmu_as *as, * allocate page in a sleeping context if GFP flags permit. Hence * spinlock needs to be unlocked and re-locked after allocation. */ - if (!(gfp & __GFP_ATOMIC)) + if (gfpflags_allow_blocking(gfp)) spin_unlock_irqrestore(&as->lock, *flags); page = alloc_page(gfp | __GFP_DMA | __GFP_ZERO); - if (!(gfp & __GFP_ATOMIC)) + if (gfpflags_allow_blocking(gfp)) spin_lock_irqsave(&as->lock, *flags); /* diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h index d88c46ca82e1..5088637fe5c2 100644 --- a/include/linux/gfp_types.h +++ b/include/linux/gfp_types.h @@ -31,7 +31,7 @@ typedef unsigned int __bitwise gfp_t; #define ___GFP_IO 0x40u #define ___GFP_FS 0x80u #define ___GFP_ZERO 0x100u -#define ___GFP_ATOMIC 0x200u +/* 0x200u unused */ #define ___GFP_DIRECT_RECLAIM 0x400u #define ___GFP_KSWAPD_RECLAIM 0x800u #define ___GFP_WRITE 0x1000u @@ -116,11 +116,8 @@ typedef unsigned int __bitwise gfp_t; * * %__GFP_HIGH indicates that the caller is high-priority and that granting * the request is necessary before the system can make forward progress. - * For example, creating an IO context to clean pages. - * - * %__GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is - * high priority. Users are typically interrupt handlers. This may be - * used in conjunction with %__GFP_HIGH + * For example creating an IO context to clean pages and requests + * from atomic context. * * %__GFP_MEMALLOC allows access to all memory. This should only be used when * the caller guarantees the allocation will allow more memory to be freed @@ -135,7 +132,6 @@ typedef unsigned int __bitwise gfp_t; * %__GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves. * This takes precedence over the %__GFP_MEMALLOC flag if both are set. */ -#define __GFP_ATOMIC ((__force gfp_t)___GFP_ATOMIC) #define __GFP_HIGH ((__force gfp_t)___GFP_HIGH) #define __GFP_MEMALLOC ((__force gfp_t)___GFP_MEMALLOC) #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) @@ -329,7 +325,7 @@ typedef unsigned int __bitwise gfp_t; * version does not attempt reclaim/compaction at all and is by default used * in page fault path, while the non-light is used by khugepaged. */ -#define GFP_ATOMIC (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM) +#define GFP_ATOMIC (__GFP_HIGH|__GFP_KSWAPD_RECLAIM) #define GFP_KERNEL (__GFP_RECLAIM | __GFP_IO | __GFP_FS) #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT) #define GFP_NOWAIT (__GFP_KSWAPD_RECLAIM) diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index e87cb2b80ed3..11524cda4a95 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -31,7 +31,6 @@ gfpflag_string(__GFP_HIGHMEM), \ gfpflag_string(GFP_DMA32), \ gfpflag_string(__GFP_HIGH), \ - gfpflag_string(__GFP_ATOMIC), \ gfpflag_string(__GFP_IO), \ gfpflag_string(__GFP_FS), \ gfpflag_string(__GFP_NOWARN), \ diff --git a/lib/test_printf.c b/lib/test_printf.c index 4bd15a593fbd..fe13de1bed5f 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -686,17 +686,17 @@ flags(void) gfp = GFP_ATOMIC|__GFP_DMA; test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp); - gfp = __GFP_ATOMIC; - test("__GFP_ATOMIC", "%pGg", &gfp); + gfp = __GFP_HIGH; + test("__GFP_HIGH", "%pGg", &gfp); /* Any flags not translated by the table should remain numeric */ gfp = ~__GFP_BITS_MASK; snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp); test(cmp_buffer, "%pGg", &gfp); - snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx", + snprintf(cmp_buffer, BUF_SIZE, "__GFP_HIGH|%#lx", (unsigned long) gfp); - gfp |= __GFP_ATOMIC; + gfp |= __GFP_HIGH; test(cmp_buffer, "%pGg", &gfp); kfree(cmp_buffer); diff --git a/mm/internal.h b/mm/internal.h index 98b1e526559d..48926b290cd5 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -24,7 +24,7 @@ struct folio_batch; #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\ __GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\ __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\ - __GFP_ATOMIC|__GFP_NOLOCKDEP) + __GFP_NOLOCKDEP) /* The GFP flags allowed during early boot */ #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS)) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6bee987ec9a3..ad6c4705a79d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4081,13 +4081,14 @@ static inline bool zone_watermark_fast(struct zone *z, unsigned int order, if (__zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags, free_pages)) return true; + /* - * Ignore watermark boosting for GFP_ATOMIC order-0 allocations + * Ignore watermark boosting for GFP_HIGH order-0 allocations * when checking the min watermark. The min watermark is the * point where boosting is ignored so that kswapd is woken up * when below the low watermark. */ - if (unlikely(!order && (gfp_mask & __GFP_ATOMIC) && z->watermark_boost + if (unlikely(!order && (alloc_flags & ALLOC_MIN_RESERVE) && z->watermark_boost && ((alloc_flags & ALLOC_WMARK_MASK) == WMARK_MIN))) { mark = z->_watermark[WMARK_MIN]; return __zone_watermark_ok(z, order, mark, highest_zoneidx, @@ -5052,14 +5053,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, unsigned int zonelist_iter_cookie; int reserve_flags; - /* - * 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))) - gfp_mask &= ~__GFP_ATOMIC; - restart: compaction_retries = 0; no_progress_loops = 0; diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c index ebfab2ca1702..4a06d83f2ac5 100644 --- a/tools/perf/builtin-kmem.c +++ b/tools/perf/builtin-kmem.c @@ -640,7 +640,6 @@ static const struct { { "__GFP_HIGHMEM", "HM" }, { "GFP_DMA32", "D32" }, { "__GFP_HIGH", "H" }, - { "__GFP_ATOMIC", "_A" }, { "__GFP_IO", "I" }, { "__GFP_FS", "F" }, { "__GFP_NOWARN", "NWR" },