From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752498AbbKBEgK (ORCPT ); Sun, 1 Nov 2015 23:36:10 -0500 Received: from mga03.intel.com ([134.134.136.65]:45244 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752221AbbKBEfg (ORCPT ); Sun, 1 Nov 2015 23:35:36 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,232,1444719600"; d="scan'208";a="592281502" Subject: [PATCH v3 02/15] dax: increase granularity of dax_clear_blocks() operations From: Dan Williams To: axboe@fb.com Cc: jack@suse.cz, linux-nvdimm@ml01.01.org, david@fromorbit.com, linux-kernel@vger.kernel.org, Jeff Moyer , Jan Kara , ross.zwisler@linux.intel.com, hch@lst.de Date: Sun, 01 Nov 2015 23:29:53 -0500 Message-ID: <20151102042952.6610.7185.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <20151102042941.6610.27784.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20151102042941.6610.27784.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f 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 dax_clear_blocks is currently performing a cond_resched() after every PAGE_SIZE memset. We need not check so frequently, for example md-raid only calls cond_resched() at stripe granularity. Also, in preparation for introducing a dax_map_atomic() operation that temporarily pins a dax mapping move the call to cond_resched() to the outer loop. Reviewed-by: Jan Kara Reviewed-by: Jeff Moyer Signed-off-by: Dan Williams --- fs/dax.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 5dc33d788d50..f8e543839e5c 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -28,6 +28,7 @@ #include #include #include +#include int dax_clear_blocks(struct inode *inode, sector_t block, long size) { @@ -38,24 +39,20 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size) do { void __pmem *addr; unsigned long pfn; - long count; + long count, sz; - count = bdev_direct_access(bdev, sector, &addr, &pfn, size); + sz = min_t(long, size, SZ_1M); + count = bdev_direct_access(bdev, sector, &addr, &pfn, sz); if (count < 0) return count; - BUG_ON(size < count); - while (count > 0) { - unsigned pgsz = PAGE_SIZE - offset_in_page(addr); - if (pgsz > count) - pgsz = count; - clear_pmem(addr, pgsz); - addr += pgsz; - size -= pgsz; - count -= pgsz; - BUG_ON(pgsz & 511); - sector += pgsz / 512; - cond_resched(); - } + if (count < sz) + sz = count; + clear_pmem(addr, sz); + addr += sz; + size -= sz; + BUG_ON(sz & 511); + sector += sz / 512; + cond_resched(); } while (size); wmb_pmem();