From patchwork Thu Jan 25 16:42:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13531391 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 58C77C48286 for ; Thu, 25 Jan 2024 16:45:16 +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=C5T1RJ9Ln+g0eZoKt7ykBMveoJwzuz6h96p9u9TAUH8=; b=NRxLUuw847iPgn 0WTwwMf3TdprbFQrt2PmbnAzm5kyoFxixXClXeYd4MvlzA4/OWfmIT6NtCVJj/rPa78VdC1NUG07J bP0nZzAdwel75ITSMbQdkcVNwf2jgNGLxNlTOlpz01VwJmJj8799nTwAp4CJe6wWoRAB6Km+ACVV3 VKdRVeYqk3fw7pCUrjtQlmmS0SX34Y/8vhREfxx2gonL6mPHDSFWtl2BT8ALRXD97/y4T8HXfisrP uyqbn9LeA6bZVzTi64iZCCdER3V0Wr5VesxHlNZl8bCcxUdyPtKNgzzWvzREB74369jysH6VFw25K Iu7az/pTVDLW4U16wz1Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rT2qe-00000000tLp-00l1; Thu, 25 Jan 2024 16:45:04 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rT2pZ-00000000sch-3WD3 for linux-arm-kernel@lists.infradead.org; Thu, 25 Jan 2024 16:44:07 +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 CDDEF1576; Thu, 25 Jan 2024 08:44:40 -0800 (PST) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DE15E3F5A1; Thu, 25 Jan 2024 08:43:50 -0800 (PST) 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 v3 12/35] mm: Call arch_swap_prepare_to_restore() before arch_swap_restore() Date: Thu, 25 Jan 2024 16:42:33 +0000 Message-Id: <20240125164256.4147-13-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240125164256.4147-1-alexandru.elisei@arm.com> References: <20240125164256.4147-1-alexandru.elisei@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240125_084358_265167_7DC4BC72 X-CRM114-Status: GOOD ( 13.47 ) 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 arm64 uses arch_swap_restore() to restore saved tags before the page is swapped in and it's called in atomic context (with the ptl lock held). Introduce arch_swap_prepare_to_restore() that will allow an architecture to perform extra work during swap in and outside of a critical section. This will be used by arm64 to allocate a buffer in memory where to temporarily save tags if tag storage is not available for the page being swapped in. Signed-off-by: Alexandru Elisei --- include/linux/pgtable.h | 7 +++++++ mm/memory.c | 4 ++++ mm/shmem.c | 9 +++++++++ mm/swapfile.c | 5 +++++ 4 files changed, 25 insertions(+) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 98f81ca08cbe..2d0f04042f62 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -959,6 +959,13 @@ static inline void arch_swap_invalidate_area(int type) } #endif +#ifndef __HAVE_ARCH_SWAP_PREPARE_TO_RESTORE +static inline vm_fault_t arch_swap_prepare_to_restore(swp_entry_t entry, struct folio *folio) +{ + return 0; +} +#endif + #ifndef __HAVE_ARCH_SWAP_RESTORE static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio) { diff --git a/mm/memory.c b/mm/memory.c index 7e1f4849463a..8a421e168b57 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3975,6 +3975,10 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) folio_throttle_swaprate(folio, GFP_KERNEL); + ret = arch_swap_prepare_to_restore(entry, folio); + if (ret) + goto out_page; + /* * Back out if somebody else already faulted in this pte. */ diff --git a/mm/shmem.c b/mm/shmem.c index 14427e9982f9..621fabc3b8c6 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1855,6 +1855,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, struct swap_info_struct *si; struct folio *folio = NULL; swp_entry_t swap; + vm_fault_t ret; int error; VM_BUG_ON(!*foliop || !xa_is_value(*foliop)); @@ -1903,6 +1904,14 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, } folio_wait_writeback(folio); + ret = arch_swap_prepare_to_restore(swap, folio); + if (ret) { + if (fault_type) + *fault_type = ret; + error = -EINVAL; + goto unlock; + } + /* * Some architectures may have to restore extra metadata to the * folio after reading from swap. diff --git a/mm/swapfile.c b/mm/swapfile.c index 556ff7347d5f..49425598f778 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1785,6 +1785,11 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, goto setpte; } + if (arch_swap_prepare_to_restore(entry, folio)) { + ret = -EINVAL; + goto out; + } + /* * Some architectures may have to restore extra metadata to the page * when reading from swap. This metadata may be indexed by swap entry