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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 315C6CA9EAE for ; Tue, 29 Oct 2019 14:15:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F148D21479 for ; Tue, 29 Oct 2019 14:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389048AbfJ2OPE (ORCPT ); Tue, 29 Oct 2019 10:15:04 -0400 Received: from mx2.suse.de ([195.135.220.15]:44096 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728994AbfJ2OPE (ORCPT ); Tue, 29 Oct 2019 10:15:04 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id AB2DFB090; Tue, 29 Oct 2019 14:15:00 +0000 (UTC) Subject: Re: [patch for-5.3 0/4] revert immediate fallback to remote hugepages To: David Rientjes Cc: Michal Hocko , Linus Torvalds , Andrea Arcangeli , Andrew Morton , Mel Gorman , "Kirill A. Shutemov" , Linux Kernel Mailing List , Linux-MM References: <20190904205522.GA9871@redhat.com> <20190909193020.GD2063@dhcp22.suse.cz> <20190925070817.GH23050@dhcp22.suse.cz> <20190927074803.GB26848@dhcp22.suse.cz> <20190930112817.GC15942@dhcp22.suse.cz> <20191001054343.GA15624@dhcp22.suse.cz> <20191001083743.GC15624@dhcp22.suse.cz> <20191018141550.GS5017@dhcp22.suse.cz> <53c4a6ca-a4d0-0862-8744-f999b17d82d8@suse.cz> From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; prefer-encrypt=mutual; keydata= mQINBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABtCBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PokCVAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJcbbyGBQkH8VTqAAoJECJPp+fMgqZkpGoP /1jhVihakxw1d67kFhPgjWrbzaeAYOJu7Oi79D8BL8Vr5dmNPygbpGpJaCHACWp+10KXj9yz fWABs01KMHnZsAIUytVsQv35DMMDzgwVmnoEIRBhisMYOQlH2bBn/dqBjtnhs7zTL4xtqEcF 1hoUFEByMOey7gm79utTk09hQE/Zo2x0Ikk98sSIKBETDCl4mkRVRlxPFl4O/w8dSaE4eczH LrKezaFiZOv6S1MUKVKzHInonrCqCNbXAHIeZa3JcXCYj1wWAjOt9R3NqcWsBGjFbkgoKMGD usiGabetmQjXNlVzyOYdAdrbpVRNVnaL91sB2j8LRD74snKsV0Wzwt90YHxDQ5z3M75YoIdl byTKu3BUuqZxkQ/emEuxZ7aRJ1Zw7cKo/IVqjWaQ1SSBDbZ8FAUPpHJxLdGxPRN8Pfw8blKY 8mvLJKoF6i9T6+EmlyzxqzOFhcc4X5ig5uQoOjTIq6zhLO+nqVZvUDd2Kz9LMOCYb516cwS/ Enpi0TcZ5ZobtLqEaL4rupjcJG418HFQ1qxC95u5FfNki+YTmu6ZLXy+1/9BDsPuZBOKYpUm 3HWSnCS8J5Ny4SSwfYPH/JrtberWTcCP/8BHmoSpS/3oL3RxrZRRVnPHFzQC6L1oKvIuyXYF rkybPXYbmNHN+jTD3X8nRqo+4Qhmu6SHi3VquQENBFsZNQwBCACuowprHNSHhPBKxaBX7qOv KAGCmAVhK0eleElKy0sCkFghTenu1sA9AV4okL84qZ9gzaEoVkgbIbDgRbKY2MGvgKxXm+kY n8tmCejKoeyVcn9Xs0K5aUZiDz4Ll9VPTiXdf8YcjDgeP6/l4kHb4uSW4Aa9ds0xgt0gP1Xb AMwBlK19YvTDZV5u3YVoGkZhspfQqLLtBKSt3FuxTCU7hxCInQd3FHGJT/IIrvm07oDO2Y8J DXWHGJ9cK49bBGmK9B4ajsbe5GxtSKFccu8BciNluF+BqbrIiM0upJq5Xqj4y+Xjrpwqm4/M ScBsV0Po7qdeqv0pEFIXKj7IgO/d4W2bABEBAAGJA3IEGAEKACYWIQSpQNQ0mSwujpkQPVAi T6fnzIKmZAUCWxk1DAIbAgUJA8JnAAFACRAiT6fnzIKmZMB0IAQZAQoAHRYhBKZ2GgCcqNxn k0Sx9r6Fd25170XjBQJbGTUMAAoJEL6Fd25170XjDBUH/2jQ7a8g+FC2qBYxU/aCAVAVY0NE YuABL4LJ5+iWwmqUh0V9+lU88Cv4/G8fWwU+hBykSXhZXNQ5QJxyR7KWGy7LiPi7Cvovu+1c 9Z9HIDNd4u7bxGKMpn19U12ATUBHAlvphzluVvXsJ23ES/F1c59d7IrgOnxqIcXxr9dcaJ2K k9VP3TfrjP3g98OKtSsyH0xMu0MCeyewf1piXyukFRRMKIErfThhmNnLiDbaVy6biCLx408L Mo4cCvEvqGKgRwyckVyo3JuhqreFeIKBOE1iHvf3x4LU8cIHdjhDP9Wf6ws1XNqIvve7oV+w B56YWoalm1rq00yUbs2RoGcXmtX1JQ//aR/paSuLGLIb3ecPB88rvEXPsizrhYUzbe1TTkKc 4a4XwW4wdc6pRPVFMdd5idQOKdeBk7NdCZXNzoieFntyPpAq+DveK01xcBoXQ2UktIFIsXey uSNdLd5m5lf7/3f0BtaY//f9grm363NUb9KBsTSnv6Vx7Co0DWaxgC3MFSUhxzBzkJNty+2d 10jvtwOWzUN+74uXGRYSq5WefQWqqQNnx+IDb4h81NmpIY/X0PqZrapNockj3WHvpbeVFAJ0 9MRzYP3x8e5OuEuJfkNnAbwRGkDy98nXW6fKeemREjr8DWfXLKFWroJzkbAVmeIL0pjXATxr +tj5JC0uvMrrXefUhXTo0SNoTsuO/OsAKOcVsV/RHHTwCDR2e3W8mOlA3QbYXsscgjghbuLh J3oTRrOQa8tUXWqcd5A0+QPo5aaMHIK0UAthZsry5EmCY3BrbXUJlt+23E93hXQvfcsmfi0N rNh81eknLLWRYvMOsrbIqEHdZBT4FHHiGjnck6EYx/8F5BAZSodRVEAgXyC8IQJ+UVa02QM5 D2VL8zRXZ6+wARKjgSrW+duohn535rG/ypd0ctLoXS6dDrFokwTQ2xrJiLbHp9G+noNTHSan ExaRzyLbvmblh3AAznb68cWmM3WVkceWACUalsoTLKF1sGrrIBj5updkKkzbKOq5gcC5AQ0E Wxk1NQEIAJ9B+lKxYlnKL5IehF1XJfknqsjuiRzj5vnvVrtFcPlSFL12VVFVUC2tT0A1Iuo9 NAoZXEeuoPf1dLDyHErrWnDyn3SmDgb83eK5YS/K363RLEMOQKWcawPJGGVTIRZgUSgGusKL NuZqE5TCqQls0x/OPljufs4gk7E1GQEgE6M90Xbp0w/r0HB49BqjUzwByut7H2wAdiNAbJWZ F5GNUS2/2IbgOhOychHdqYpWTqyLgRpf+atqkmpIJwFRVhQUfwztuybgJLGJ6vmh/LyNMRr8 J++SqkpOFMwJA81kpjuGR7moSrUIGTbDGFfjxmskQV/W/c25Xc6KaCwXah3OJ40AEQEAAYkC PAQYAQoAJhYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJbGTU1AhsMBQkDwmcAAAoJECJPp+fM gqZkPN4P/Ra4NbETHRj5/fM1fjtngt4dKeX/6McUPDIRuc58B6FuCQxtk7sX3ELs+1+w3eSV rHI5cOFRSdgw/iKwwBix8D4Qq0cnympZ622KJL2wpTPRLlNaFLoe5PkoORAjVxLGplvQIlhg miljQ3R63ty3+MZfkSVsYITlVkYlHaSwP2t8g7yTVa+q8ZAx0NT9uGWc/1Sg8j/uoPGrctml hFNGBTYyPq6mGW9jqaQ8en3ZmmJyw3CHwxZ5FZQ5qc55xgshKiy8jEtxh+dgB9d8zE/S/UGI E99N/q+kEKSgSMQMJ/CYPHQJVTi4YHh1yq/qTkHRX+ortrF5VEeDJDv+SljNStIxUdroPD29 2ijoaMFTAU+uBtE14UP5F+LWdmRdEGS1Ah1NwooL27uAFllTDQxDhg/+LJ/TqB8ZuidOIy1B xVKRSg3I2m+DUTVqBy7Lixo73hnW69kSjtqCeamY/NSu6LNP+b0wAOKhwz9hBEwEHLp05+mj 5ZFJyfGsOiNUcMoO/17FO4EBxSDP3FDLllpuzlFD7SXkfJaMWYmXIlO0jLzdfwfcnDzBbPwO hBM8hvtsyq8lq8vJOxv6XD6xcTtj5Az8t2JjdUX6SF9hxJpwhBU0wrCoGDkWp4Bbv6jnF7zP Nzftr4l8RuJoywDIiJpdaNpSlXKpj/K6KrnyAI/joYc7 Message-ID: <08a3f4dd-c3ce-0009-86c5-9ee51aba8557@suse.cz> Date: Tue, 29 Oct 2019 15:14:59 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/24/19 8:59 PM, David Rientjes wrote: >> diff --git a/mm/mempolicy.c b/mm/mempolicy.c >> index 4ae967bcf954..2c48146f3ee2 100644 >> --- a/mm/mempolicy.c >> +++ b/mm/mempolicy.c >> @@ -2129,18 +2129,20 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, >> nmask = policy_nodemask(gfp, pol); >> if (!nmask || node_isset(hpage_node, *nmask)) { >> mpol_cond_put(pol); >> + /* >> + * First, try to allocate THP only on local node, but >> + * don't reclaim unnecessarily, just compact. >> + */ >> page = __alloc_pages_node(hpage_node, >> - gfp | __GFP_THISNODE, order); >> + gfp | __GFP_THISNODE | __GFP_NORETRY, order); >> >> /* >> - * If hugepage allocations are configured to always >> - * synchronous compact or the vma has been madvised >> - * to prefer hugepage backing, retry allowing remote >> - * memory as well. >> + * If that fails, allow both compaction and reclaim, >> + * but on all nodes. >> */ >> - if (!page && (gfp & __GFP_DIRECT_RECLAIM)) >> + if (!page) >> page = __alloc_pages_node(hpage_node, >> - gfp | __GFP_NORETRY, order); >> + gfp, order); >> >> goto out; >> } > Hi Vlastimil, > > For the default case where thp enabled is not set to "always" and the VMA I assume you meant "defrag" instead of "enabled". > is not madvised for MADV_HUGEPAGE, how does this prefer to return node > local pages rather than remote hugepages? The idea is to optimize for > access latency when the vma has not been explicitly madvised. Right, you mentioned this before IIRC, and I forgot. How about this? We could be also smarter and consolidate to a single attempt if there's actually just a single NUMA node, but that can be optimized later. ----8<---- >From 4c3a2217d0ee5ead00b1443010d07c664b6ac645 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Tue, 1 Oct 2019 14:20:58 +0200 Subject: [PATCH] mm, thp: tweak reclaim/compaction effort of local-only and all-node allocations THP page faults now attempt a __GFP_THISNODE allocation first, which should only compact existing free memory, followed by another attempt that can allocate from any node using reclaim/compaction effort specified by global defrag setting and madvise. This patch makes the following changes to the scheme: - before the patch, the first allocation relies on a check for pageblock order and __GFP_IO to prevent excessive reclaim. This however affects also the second attempt, which is not limited to single node. Instead of that, reuse the existing check for costly order __GFP_NORETRY allocations, and make sure the first THP attempt uses __GFP_NORETRY. As a side-effect, all costly order __GFP_NORETRY allocations will bail out if compaction needs reclaim, while previously they only bailed out when compaction was deferred due to previous failures. This should be still acceptable within the __GFP_NORETRY semantics. - before the patch, the second allocation attempt (on all nodes) was passing __GFP_NORETRY. This is redundant as the check for pageblock order (discussed above) was stronger. It's also contrary to madvise(MADV_HUGEPAGE) which means some effort to allocate THP is requested. After this patch, the second attempt doesn't pass __GFP_THISNODE nor __GFP_NORETRY. To sum up, THP page faults now try the following attempts: 1. local node only THP allocation with no reclaim, just compaction. 2. for madvised VMA's or when synchronous compaction is enabled always - THP allocation from any node with effort determined by global defrag setting and VMA madvise 3. fallback to base pages on any node Signed-off-by: Vlastimil Babka --- mm/mempolicy.c | 10 +++++++--- mm/page_alloc.c | 24 +++++------------------- 2 files changed, 12 insertions(+), 22 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4ae967bcf954..ed6fbc5b1e20 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2129,18 +2129,22 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, nmask = policy_nodemask(gfp, pol); if (!nmask || node_isset(hpage_node, *nmask)) { mpol_cond_put(pol); + /* + * First, try to allocate THP only on local node, but + * don't reclaim unnecessarily, just compact. + */ page = __alloc_pages_node(hpage_node, - gfp | __GFP_THISNODE, order); + gfp | __GFP_THISNODE | __GFP_NORETRY, order); /* * If hugepage allocations are configured to always * synchronous compact or the vma has been madvised * to prefer hugepage backing, retry allowing remote - * memory as well. + * memory with both reclaim and compact as well. */ if (!page && (gfp & __GFP_DIRECT_RECLAIM)) page = __alloc_pages_node(hpage_node, - gfp | __GFP_NORETRY, order); + gfp, order); goto out; } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ecc3dbad606b..36d7d852f7b1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4473,8 +4473,11 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, if (page) goto got_pg; - if (order >= pageblock_order && (gfp_mask & __GFP_IO) && - !(gfp_mask & __GFP_RETRY_MAYFAIL)) { + /* + * Checks for costly allocations with __GFP_NORETRY, which + * includes some THP page fault allocations + */ + if (costly_order && (gfp_mask & __GFP_NORETRY)) { /* * If allocating entire pageblock(s) and compaction * failed because all zones are below low watermarks @@ -4495,23 +4498,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, if (compact_result == COMPACT_SKIPPED || compact_result == COMPACT_DEFERRED) goto nopage; - } - - /* - * Checks for costly allocations with __GFP_NORETRY, which - * includes THP page fault allocations - */ - if (costly_order && (gfp_mask & __GFP_NORETRY)) { - /* - * If compaction is deferred for high-order allocations, - * it is because sync compaction recently failed. If - * this is the case and the caller requested a THP - * allocation, we do not want to heavily disrupt the - * system, so we fail the allocation instead of entering - * direct reclaim. - */ - if (compact_result == COMPACT_DEFERRED) - goto nopage; /* * Looks like reclaim/compaction is worth trying, but -- 2.23.0