From patchwork Mon Oct 11 03:00:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jingbo Xu X-Patchwork-Id: 12548957 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72ADFC4167B for ; Mon, 11 Oct 2021 03:01:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 588F66054F for ; Mon, 11 Oct 2021 03:01:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233739AbhJKDDA (ORCPT ); Sun, 10 Oct 2021 23:03:00 -0400 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:57732 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233654AbhJKDC4 (ORCPT ); Sun, 10 Oct 2021 23:02:56 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0UrJTlCR_1633921255; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0UrJTlCR_1633921255) by smtp.aliyun-inc.com(127.0.0.1); Mon, 11 Oct 2021 11:00:56 +0800 From: Jeffle Xu To: vgoyal@redhat.com, stefanha@redhat.com, miklos@szeredi.hub Cc: linux-fsdevel@vger.kernel.org, virtio-fs@redhat.com, bo.liu@linux.alibaba.com, joseph.qi@linux.alibaba.com Subject: [PATCH v6 5/7] fuse: enable per-file DAX Date: Mon, 11 Oct 2021 11:00:50 +0800 Message-Id: <20211011030052.98923-6-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211011030052.98923-1-jefflexu@linux.alibaba.com> References: <20211011030052.98923-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org DAX may be limited in some specific situation. When the number of usable DAX windows is under watermark, the recalim routine will be triggered to reclaim some DAX windows. It may have a negative impact on the performance, since some processes may need to wait for DAX windows to be recalimed and reused then. To mitigate the performance degradation, the overall DAX window need to be expanded larger. However, simply expanding the DAX window may not be a good deal in some scenario. To maintain one DAX window chunk (i.e., 2MB in size), 32KB (512 * 64 bytes) memory footprint will be consumed for page descriptors inside guest, which is greater than the memory footprint if it uses guest page cache when DAX disabled. Thus it'd better disable DAX for those files smaller than 32KB, to reduce the demand for DAX window and thus avoid the unworthy memory overhead. Per-file DAX feature is introduced to address this issue, by offering a finer grained control for dax to users, trying to achieve a balance between performance and memory overhead. The FUSE_ATTR_DAX flag in FUSE_LOOKUP reply is used to indicate whether DAX should be enabled or not for corresponding file. Currently the state whether DAX is enabled or not for the file is initialized only when inode is instantiated. Signed-off-by: Jeffle Xu --- fs/fuse/dax.c | 8 ++++---- fs/fuse/file.c | 4 ++-- fs/fuse/fuse_i.h | 4 ++-- fs/fuse/inode.c | 2 +- 4 files changed, 9 insertions(+), 9 deletions(-) diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c index 4c6c64efc950..15bde36829b8 100644 --- a/fs/fuse/dax.c +++ b/fs/fuse/dax.c @@ -1335,7 +1335,7 @@ static const struct address_space_operations fuse_dax_file_aops = { .invalidatepage = noop_invalidatepage, }; -static bool fuse_should_enable_dax(struct inode *inode) +static bool fuse_should_enable_dax(struct inode *inode, unsigned int flags) { struct fuse_conn *fc = get_fuse_conn(inode); unsigned int dax_mode = fc->dax_mode; @@ -1352,12 +1352,12 @@ static bool fuse_should_enable_dax(struct inode *inode) return true; /* dax_mode == FUSE_DAX_INODE */ - return true; + return flags & FUSE_ATTR_DAX; } -void fuse_dax_inode_init(struct inode *inode) +void fuse_dax_inode_init(struct inode *inode, unsigned int flags) { - if (!fuse_should_enable_dax(inode)) + if (!fuse_should_enable_dax(inode, flags)) return; inode->i_flags |= S_DAX; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 11404f8c21c7..40c667a48cf6 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -3163,7 +3163,7 @@ static const struct address_space_operations fuse_file_aops = { .write_end = fuse_write_end, }; -void fuse_init_file_inode(struct inode *inode) +void fuse_init_file_inode(struct inode *inode, unsigned int flags) { struct fuse_inode *fi = get_fuse_inode(inode); @@ -3177,5 +3177,5 @@ void fuse_init_file_inode(struct inode *inode) fi->writepages = RB_ROOT; if (IS_ENABLED(CONFIG_FUSE_DAX)) - fuse_dax_inode_init(inode); + fuse_dax_inode_init(inode, flags); } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 5abf9749923f..0270a41c31d7 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1016,7 +1016,7 @@ int fuse_notify_poll_wakeup(struct fuse_conn *fc, /** * Initialize file operations on a regular file */ -void fuse_init_file_inode(struct inode *inode); +void fuse_init_file_inode(struct inode *inode, unsigned int flags); /** * Initialize inode operations on regular files and special files @@ -1268,7 +1268,7 @@ int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode, struct dax_device *dax_dev); void fuse_dax_conn_free(struct fuse_conn *fc); bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi); -void fuse_dax_inode_init(struct inode *inode); +void fuse_dax_inode_init(struct inode *inode, unsigned int flags); void fuse_dax_inode_cleanup(struct inode *inode); bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment); void fuse_dax_cancel_work(struct fuse_conn *fc); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index f4ad99e2415b..73f19cd6e702 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -280,7 +280,7 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) inode->i_ctime.tv_nsec = attr->ctimensec; if (S_ISREG(inode->i_mode)) { fuse_init_common(inode); - fuse_init_file_inode(inode); + fuse_init_file_inode(inode, attr->flags); } else if (S_ISDIR(inode->i_mode)) fuse_init_dir(inode); else if (S_ISLNK(inode->i_mode))