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 2FD18C636CC for ; Fri, 3 Feb 2023 06:40:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232159AbjBCGke (ORCPT ); Fri, 3 Feb 2023 01:40:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232463AbjBCGj3 (ORCPT ); Fri, 3 Feb 2023 01:39:29 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF50C8EB4D for ; Thu, 2 Feb 2023 22:37:01 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6B0EFB82985 for ; Fri, 3 Feb 2023 06:37:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04AC2C433D2; Fri, 3 Feb 2023 06:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1675406220; bh=IfuCWJXJOwVeRYt0oBZrArgYY9f5rcigy1MRM/mF+OY=; h=Date:To:From:Subject:From; b=aKURumTpr/GecgLbsiRg8CodeZrZ7rXddVJ6pcY4CaVOsOnHIJ3aaql72hsDz9NcM 7oEYdRmsCnhiW0EApR2/wf27s61Sa3F+MaQuYPPPbtebFixuxyHf1JQYmy/U2okEwk 7x5KUI/Gv9ojq8jB/SEsCxSWK/GAS5V4xdWu3yl4= Date: Thu, 02 Feb 2023 22:36:59 -0800 To: mm-commits@vger.kernel.org, willy@infradead.org, vbabka@suse.cz, thierry.reding@gmail.com, neilb@suse.de, mhocko@suse.com, mgorman@techsingularity.net, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-page_alloc-explicitly-define-how-__gfp_high-non-blocking-allocations-accesses-reserves.patch removed from -mm tree Message-Id: <20230203063700.04AC2C433D2@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm/page_alloc: explicitly define how __GFP_HIGH non-blocking allocations accesses reserves has been removed from the -mm tree. Its filename was mm-page_alloc-explicitly-define-how-__gfp_high-non-blocking-allocations-accesses-reserves.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Mel Gorman Subject: mm/page_alloc: explicitly define how __GFP_HIGH non-blocking allocations accesses reserves Date: Fri, 13 Jan 2023 11:12:16 +0000 GFP_ATOMIC allocations get flagged ALLOC_HARDER which is a vague description. In preparation for the removal of GFP_ATOMIC redefine __GFP_ATOMIC to simply mean non-blocking and renaming ALLOC_HARDER to ALLOC_NON_BLOCK accordingly. __GFP_HIGH is required for access to reserves but non-blocking is granted more access. For example, GFP_NOWAIT is non-blocking but has no special access to reserves. A __GFP_NOFAIL blocking allocation is granted access similar to __GFP_HIGH if the only alternative is an OOM kill. Link: https://lkml.kernel.org/r/20230113111217.14134-6-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Michal Hocko Cc: Matthew Wilcox Cc: NeilBrown Cc: Thierry Reding Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- --- a/mm/internal.h~mm-page_alloc-explicitly-define-how-__gfp_high-non-blocking-allocations-accesses-reserves +++ a/mm/internal.h @@ -778,7 +778,10 @@ unsigned int reclaim_clean_pages_from_li #define ALLOC_OOM ALLOC_NO_WATERMARKS #endif -#define ALLOC_HARDER 0x10 /* try to alloc harder */ +#define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access + * to 25% of the min watermark or + * 62.5% if __GFP_HIGH is set. + */ #define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50% * of the min watermark. */ @@ -793,7 +796,7 @@ unsigned int reclaim_clean_pages_from_li #define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */ /* Flags that allow allocations below the min watermark. */ -#define ALLOC_RESERVES (ALLOC_HARDER|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM) +#define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM) enum ttu_flags; struct tlbflush_unmap_batch; --- a/mm/page_alloc.c~mm-page_alloc-explicitly-define-how-__gfp_high-non-blocking-allocations-accesses-reserves +++ a/mm/page_alloc.c @@ -4007,18 +4007,19 @@ bool __zone_watermark_ok(struct zone *z, * __GFP_HIGH allows access to 50% of the min reserve as well * as OOM. */ - if (alloc_flags & ALLOC_MIN_RESERVE) + if (alloc_flags & ALLOC_MIN_RESERVE) { min -= min / 2; - /* - * Non-blocking allocations can access some of the reserve - * with more access if also __GFP_HIGH. The reasoning is that - * a non-blocking caller may incur a more severe penalty - * if it cannot get memory quickly, particularly if it's - * also __GFP_HIGH. - */ - if (alloc_flags & ALLOC_HARDER) - min -= min / 4; + /* + * Non-blocking allocations (e.g. GFP_ATOMIC) can + * access more reserves than just __GFP_HIGH. Other + * non-blocking allocations requests such as GFP_NOWAIT + * or (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) do not get + * access to the min reserve. + */ + if (alloc_flags & ALLOC_NON_BLOCK) + min -= min / 4; + } /* * OOM victims can try even harder than the normal reserve @@ -4869,28 +4870,30 @@ gfp_to_alloc_flags(gfp_t gfp_mask, unsig * The caller may dip into page reserves a bit more if the caller * cannot run direct reclaim, or if the caller has realtime scheduling * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will - * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_MIN_RESERVE(__GFP_HIGH). + * set both ALLOC_NON_BLOCK and ALLOC_MIN_RESERVE(__GFP_HIGH). */ alloc_flags |= (__force int) (gfp_mask & (__GFP_HIGH | __GFP_KSWAPD_RECLAIM)); - if (gfp_mask & __GFP_ATOMIC) { + if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) { /* * Not worth trying to allocate harder for __GFP_NOMEMALLOC even * if it can't schedule. */ if (!(gfp_mask & __GFP_NOMEMALLOC)) { - alloc_flags |= ALLOC_HARDER; + alloc_flags |= ALLOC_NON_BLOCK; if (order > 0) alloc_flags |= ALLOC_HIGHATOMIC; } /* - * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the - * comment for __cpuset_node_allowed(). + * Ignore cpuset mems for non-blocking __GFP_HIGH (probably + * GFP_ATOMIC) rather than fail, see the comment for + * __cpuset_node_allowed(). */ - alloc_flags &= ~ALLOC_CPUSET; + if (alloc_flags & ALLOC_MIN_RESERVE) + alloc_flags &= ~ALLOC_CPUSET; } else if (unlikely(rt_task(current)) && in_task()) alloc_flags |= ALLOC_MIN_RESERVE; @@ -5321,12 +5324,13 @@ nopage: WARN_ON_ONCE_GFP(costly_order, gfp_mask); /* - * Help non-failing allocations by giving them access to memory - * reserves but do not use ALLOC_NO_WATERMARKS because this + * Help non-failing allocations by giving some access to memory + * reserves normally used for high priority non-blocking + * allocations but do not use ALLOC_NO_WATERMARKS because this * could deplete whole memory reserves which would just make - * the situation worse + * the situation worse. */ - page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac); + page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_MIN_RESERVE, ac); if (page) goto got_pg; _ Patches currently in -mm which might be from mgorman@techsingularity.net are