From patchwork Sun Nov 19 16:57:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13460569 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BBAA01706; Sun, 19 Nov 2023 08:58:32 -0800 (PST) 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 87A641042; Sun, 19 Nov 2023 08:59:18 -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 40DE23F6C4; Sun, 19 Nov 2023 08:58:27 -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 v2 10/27] mm: Call arch_swap_prepare_to_restore() before arch_swap_restore() Date: Sun, 19 Nov 2023 16:57:04 +0000 Message-Id: <20231119165721.9849-11-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231119165721.9849-1-alexandru.elisei@arm.com> References: <20231119165721.9849-1-alexandru.elisei@arm.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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. Signed-off-by: Alexandru Elisei --- include/linux/pgtable.h | 7 +++++++ mm/memory.c | 4 ++++ mm/shmem.c | 9 +++++++++ mm/swapfile.c | 7 +++++++ 4 files changed, 27 insertions(+) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index b1001ce361ac..ffdb9b6bed6c 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -938,6 +938,13 @@ 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 1f18ed4a5497..e137f7673749 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3957,6 +3957,10 @@ 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 71ce5fe5c779..0449c03dbdfd 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1840,6 +1840,7 @@ 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)); @@ -1888,6 +1889,14 @@ 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 4bc70f459164..9983dffce47b 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1746,6 +1746,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, spinlock_t *ptl; pte_t *pte, new_pte, old_pte; bool hwpoisoned = PageHWPoison(page); + vm_fault_t err; int ret = 1; swapcache = page; @@ -1779,6 +1780,12 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, goto setpte; } + err = arch_swap_prepare_to_restore(entry, page_folio(page)); + if (err) { + 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