From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932644Ab2ISQdY (ORCPT ); Wed, 19 Sep 2012 12:33:24 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:26362 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932613Ab2ISQdV (ORCPT ); Wed, 19 Sep 2012 12:33:21 -0400 Subject: [PATCH 11/11] fuse: optimize __fuse_direct_io() To: miklos@szeredi.hu From: Maxim Patlasov Cc: fuse-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, devel@openvz.org Date: Wed, 19 Sep 2012 20:33:31 +0400 Message-ID: <20120919163327.29482.56965.stgit@maximpc.sw.ru> In-Reply-To: <20120919161559.29482.55120.stgit@maximpc.sw.ru> References: <20120919161559.29482.55120.stgit@maximpc.sw.ru> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org __fuse_direct_io() allocates fuse-requests by calling fuse_get_req(fc, n). The patch calculates 'n' based on iov[] array. This is useful because allocating FUSE_MAX_PAGES_PER_REQ page pointers and descriptors for each fuse request would be waste of memory in case of iov-s of smaller size. Signed-off-by: Maxim Patlasov --- fs/fuse/file.c | 27 +++++++++++++++++++++++---- 1 files changed, 23 insertions(+), 4 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 5b0fa5d..5ecab19 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1090,14 +1090,14 @@ static int fuse_get_user_pages(struct fuse_req *req, return 0; } - while (nbytes < *nbytesp && req->num_pages < FUSE_MAX_PAGES_PER_REQ) { + while (nbytes < *nbytesp && req->num_pages < req->max_pages) { int npages; unsigned long user_addr = fuse_get_ua(*iov_pp, *iov_offset_p); unsigned offset = user_addr & ~PAGE_MASK; size_t frag_size = fuse_get_fr_sz(*iov_pp, *iov_offset_p, *nbytesp - nbytes); - int n = FUSE_MAX_PAGES_PER_REQ - req->num_pages; + int n = req->max_pages - req->num_pages; frag_size = min_t(size_t, frag_size, n << PAGE_SHIFT); npages = (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; @@ -1138,6 +1138,24 @@ static int fuse_get_user_pages(struct fuse_req *req, return 0; } +static inline int fuse_iov_npages(const struct iovec *iov, + unsigned long nr_segs, size_t iov_offset) +{ + int npages = 0; + + while (nr_segs-- > 0 && npages < FUSE_MAX_PAGES_PER_REQ) { + unsigned long user_addr = fuse_get_ua(iov, iov_offset); + unsigned offset = user_addr & ~PAGE_MASK; + size_t frag_size = iov->iov_len - iov_offset; + + npages += (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; + iov++; + iov_offset = 0; + } + + return min(npages, FUSE_MAX_PAGES_PER_REQ); +} + static ssize_t __fuse_direct_io(struct file *file, const struct iovec *iov, unsigned long nr_segs, size_t count, loff_t *ppos, int write) @@ -1150,7 +1168,7 @@ static ssize_t __fuse_direct_io(struct file *file, const struct iovec *iov, struct fuse_req *req; size_t iov_offset = 0; - req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ); + req = fuse_get_req(fc, fuse_iov_npages(iov, nr_segs, iov_offset)); if (IS_ERR(req)) return PTR_ERR(req); @@ -1186,7 +1204,8 @@ static ssize_t __fuse_direct_io(struct file *file, const struct iovec *iov, break; if (count) { fuse_put_request(fc, req); - req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ); + req = fuse_get_req(fc, + fuse_iov_npages(iov, nr_segs, iov_offset)); if (IS_ERR(req)) break; }