From 40d344ec5ee440596b1f3ae87556e20c7197757a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 5 Dec 2011 08:53:21 +0000 Subject: xfs: mark the xfssyncd workqueue as non-reentrant On a system with lots of memory pressure that is stuck on synchronous inode reclaim the workqueue code will run one instance of the inode reclaim work item on every CPU. which is not what we want. Make sure to mark the xfssyncd workqueue as non-reentrant to make sure there only is one instace of each running globally. Also stop using special paramater for the workqueue; now that we guarantee each fs has only running one of each works at a time there is no need to artificially lower max_active and compensate for that by setting the WQ_CPU_INTENSIVE flag. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Ben Myers diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 88cd0c8..5f955f4 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1625,12 +1625,12 @@ STATIC int __init xfs_init_workqueues(void) { /* - * max_active is set to 8 to give enough concurency to allow - * multiple work operations on each CPU to run. This allows multiple - * filesystems to be running sync work concurrently, and scales with - * the number of CPUs in the system. + * We never want to the same work item to run twice, reclaiming inodes + * or idling the log is not going to get any faster by multiple CPUs + * competing for ressources. Use the default large max_active value + * so that even lots of filesystems can perform these task in parallel. */ - xfs_syncd_wq = alloc_workqueue("xfssyncd", WQ_CPU_INTENSIVE, 8); + xfs_syncd_wq = alloc_workqueue("xfssyncd", WQ_NON_REENTRANT, 0); if (!xfs_syncd_wq) return -ENOMEM; return 0; -- cgit v0.10.2