From patchwork Wed Aug 23 13:13:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13362338 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5B055EE49A3 for ; Wed, 23 Aug 2023 13:15:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9EEr1uuy5rJZk+mKf6/xw5FdN8w+1OsUN5BWcmqhtX4=; b=WZ8sa+mLDd7LLq UU8YmDIrMd/V6FPhyh/GkXQOAXNGew2zo69/zJe6GLmOlCQCHLzB1xUj/mEA6/ruHyM/mtiI6Uyqs mIoXf1+fK1ycCj9f0wb/Qpf5rEo/OaHpjbIlZS5AcGsERePPrBGvycjQvu/3jIga5qJRHt+XffmDn dE1R2wHKiBSf+wDAwblqVD1wWR+ThXTO4QyzRlw+wuzKIpko1SEeE8F0x5xcMxHgljBnZ18qLjAtu LzRGy7ubYBBCgRfSgQNmUC87RrefnKxVDIlfNCAeuLg2xn+PTtVqgS74BL5yIpzPc8zgUFkZm9x0S RIwv7zUjtN26bldxr3wg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qYnha-000cbk-1y; Wed, 23 Aug 2023 13:15:14 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qYnhG-000cPi-1I for linux-arm-kernel@lists.infradead.org; Wed, 23 Aug 2023 13:14:56 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B6AC91595; Wed, 23 Aug 2023 06:15:33 -0700 (PDT) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 51AF33F740; Wed, 23 Aug 2023 06:14:47 -0700 (PDT) From: Alexandru Elisei To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC 07/37] mm: page_alloc: Bypass pcp when freeing MIGRATE_METADATA pages Date: Wed, 23 Aug 2023 14:13:20 +0100 Message-Id: <20230823131350.114942-8-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230823131350.114942-1-alexandru.elisei@arm.com> References: <20230823131350.114942-1-alexandru.elisei@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230823_061454_495106_CF81FF40 X-CRM114-Status: GOOD ( 14.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org When a metadata page is returned to the page allocator because all the associated pages with metadata were freed, the page will be returned to the pcp list, which makes it very likely that it will be used to satisfy an allocation request. This is not optimal, because metadata pages should be used as a last resort, to increase the chances they are not in use when they are needed, to avoid costly page migration. Bypass the pcp lists when freeing metadata pages. Note that metadata pages can still end up on the pcp lists when a list is refilled, but this should only happen when memory is running low, which is as intended Signed-off-by: Alexandru Elisei --- mm/page_alloc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a693e23c4733..bbb49b489230 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2478,7 +2478,8 @@ void free_unref_page(struct page *page, unsigned int order) */ migratetype = get_pcppage_migratetype(page); if (unlikely(migratetype >= MIGRATE_PCPTYPES)) { - if (unlikely(is_migrate_isolate(migratetype))) { + if (unlikely(is_migrate_isolate(migratetype) || + is_migrate_metadata(migratetype))) { free_one_page(page_zone(page), page, pfn, order, migratetype, FPI_NONE); return; } @@ -2522,7 +2523,8 @@ void free_unref_page_list(struct list_head *list) * comment in free_unref_page. */ migratetype = get_pcppage_migratetype(page); - if (unlikely(is_migrate_isolate(migratetype))) { + if (unlikely(is_migrate_isolate(migratetype) || + is_migrate_metadata(migratetype))) { list_del(&page->lru); free_one_page(page_zone(page), page, pfn, 0, migratetype, FPI_NONE); continue;