From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.126.com (m16.mail.126.com [117.135.210.7]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AAA2D372 for ; Tue, 2 Jul 2024 04:00:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719892848; cv=none; b=qt37MFluTydjZSiS6oXsjMSykmE7lIoJnyDvAMzTDmJIkWmZbpdTaboSMVrpxzOZunfaqQ7T0Y7d4F/OtaMpQxnQF5BO0sIR97jPnimrSb1i5eLUvnwJU+CjQwyzTy5fdYeK5TRJihB0ybop1PxCw0ORXcQWc5L8Jqqep+Znirg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719892848; c=relaxed/simple; bh=bZt0T2cK/rmJ0tqgfXoo7VJSAXytJmDIL47DaqmRolg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=LsC5C7pa2Xb3YYrUAq5ofES/cO1Idf/lxYFr6VvDiPtx1TUzWOgGY7wlNwEGwsuJPhKEbP3Jvctx3dVPJSe02OHWiT5BTKMUcLCwF0Pm9WpHB/qaS8U92CBPiVU6vRzgret8hZfmXBkoO3XVYGKex5QP+MNs1TirKfs492vSqcg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com; spf=pass smtp.mailfrom=126.com; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b=U6eyl5Ku; arc=none smtp.client-ip=117.135.210.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=126.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b="U6eyl5Ku" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=From:Subject:Date:Message-Id; bh=RY36AjDXcAyFVoRr26 WPEHCNW7nl/sNLNFyyVSycf1A=; b=U6eyl5Ku0i2PiOUQaI/0ZL1PGq08HcKD5f 3EVcZxyxrQ1N041oLGofBSVOmCjN1AYYTYploJb54/1gnL/F8ua1SwTXEMsUGk0T gjdbHybECo+6r1/9MQsld/Sus7jrGfRGT2PYHCYXzb3Hq4Abi2fe6aGTIcWfLSxc pArrWU67c= Received: from hg-OptiPlex-7040.hygon.cn (unknown [118.242.3.34]) by gzga-smtp-mta-g1-5 (Coremail) with SMTP id _____wDnT6FVe4NmEmgHAQ--.8225S2; Tue, 02 Jul 2024 12:00:22 +0800 (CST) From: yangge1116@126.com To: stable@vger.kernel.org Cc: yangge1116@126.com, 21cnbao@gmail.com, akpm@linux-foundation.org, baolin.wang@linux.alibaba.com, mgorman@techsingularity.net, liuzixing@hygon.cn Subject: [PATCH 6.1.y] mm/page_alloc: Separate THP PCP into movable and non-movable categories Date: Tue, 2 Jul 2024 12:00:19 +0800 Message-Id: <1719892819-2868-1-git-send-email-yangge1116@126.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <2024070129-movable-commend-1b2a@gregkh> References: <2024070129-movable-commend-1b2a@gregkh> X-CM-TRANSID:_____wDnT6FVe4NmEmgHAQ--.8225S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxAFWUtF17Xw18JF1UuFWDXFb_yoWruw4xpF WxGr1ay3yjq343Aw1xA3WqkryrC3ZxGFsrGrW09348ZwsxJFyS9as7KF1qvFy8ZrW5AF4U Xr9rt3s3CF4DZ37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jYxRDUUUUU= X-CM-SenderInfo: 51dqwwjhrrila6rslhhfrp/1tbiWRcQG2VLbGyA9QAAse Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: From: yangge Since commit 5d0a661d808f ("mm/page_alloc: use only one PCP list for THP-sized allocations") no longer differentiates the migration type of pages in THP-sized PCP list, it's possible that non-movable allocation requests may get a CMA page from the list, in some cases, it's not acceptable. If a large number of CMA memory are configured in system (for example, the CMA memory accounts for 50% of the system memory), starting a virtual machine with device passthrough will get stuck. During starting the virtual machine, it will call pin_user_pages_remote(..., FOLL_LONGTERM, ...) to pin memory. Normally if a page is present and in CMA area, pin_user_pages_remote() will migrate the page from CMA area to non-CMA area because of FOLL_LONGTERM flag. But if non-movable allocation requests return CMA memory, migrate_longterm_unpinnable_pages() will migrate a CMA page to another CMA page, which will fail to pass the check in check_and_migrate_movable_pages() and cause migration endless. Call trace: pin_user_pages_remote --__gup_longterm_locked // endless loops in this function ----_get_user_pages_locked ----check_and_migrate_movable_pages ------migrate_longterm_unpinnable_pages --------alloc_migration_target This problem will also have a negative impact on CMA itself. For example, when CMA is borrowed by THP, and we need to reclaim it through cma_alloc() or dma_alloc_coherent(), we must move those pages out to ensure CMA's users can retrieve that contigous memory. Currently, CMA's memory is occupied by non-movable pages, meaning we can't relocate them. As a result, cma_alloc() is more likely to fail. To fix the problem above, we add one PCP list for THP, which will not introduce a new cacheline for struct per_cpu_pages. THP will have 2 PCP lists, one PCP list is used by MOVABLE allocation, and the other PCP list is used by UNMOVABLE allocation. MOVABLE allocation contains GPF_MOVABLE, and UNMOVABLE allocation contains GFP_UNMOVABLE and GFP_RECLAIMABLE. Link: https://lkml.kernel.org/r/1718845190-4456-1-git-send-email-yangge1116@126.com Fixes: 5d0a661d808f ("mm/page_alloc: use only one PCP list for THP-sized allocations") Signed-off-by: yangge Cc: Baolin Wang Cc: Barry Song <21cnbao@gmail.com> Cc: Mel Gorman Cc: Signed-off-by: Andrew Morton (cherry picked from commit bf14ed81f571f8dba31cd72ab2e50fbcc877cc31) Signed-off-by: yangge --- include/linux/mmzone.h | 9 ++++----- mm/page_alloc.c | 8 ++++++-- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 3b9f4d7..93d2003 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -552,13 +552,12 @@ enum zone_watermarks { }; /* - * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. One additional list - * for THP which will usually be GFP_MOVABLE. Even if it is another type, - * it should not contribute to serious fragmentation causing THP allocation - * failures. + * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. Two additional lists + * are added for THP. One PCP list is used by GPF_MOVABLE, and the other PCP list + * is used by GFP_UNMOVABLE and GFP_RECLAIMABLE. */ #ifdef CONFIG_TRANSPARENT_HUGEPAGE -#define NR_PCP_THP 1 +#define NR_PCP_THP 2 #else #define NR_PCP_THP 0 #endif diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a7537da..1241226 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -705,12 +705,16 @@ static void bad_page(struct page *page, const char *reason) static inline unsigned int order_to_pindex(int migratetype, int order) { + bool __maybe_unused movable; int base = order; #ifdef CONFIG_TRANSPARENT_HUGEPAGE if (order > PAGE_ALLOC_COSTLY_ORDER) { VM_BUG_ON(order != pageblock_order); - return NR_LOWORDER_PCP_LISTS; + + movable = migratetype == MIGRATE_MOVABLE; + + return NR_LOWORDER_PCP_LISTS + movable; } #else VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER); @@ -724,7 +728,7 @@ static inline int pindex_to_order(unsigned int pindex) int order = pindex / MIGRATE_PCPTYPES; #ifdef CONFIG_TRANSPARENT_HUGEPAGE - if (pindex == NR_LOWORDER_PCP_LISTS) + if (pindex >= NR_LOWORDER_PCP_LISTS) order = pageblock_order; #else VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER); -- 2.7.4