From: Jan Kara Subject: Re: [RFC v3] [PATCH 0/18] DAX page fault locking Date: Wed, 11 May 2016 11:19:30 +0200 Message-ID: <20160511091930.GE14744@quack2.suse.cz> References: <1461015341-20153-1-git-send-email-jack@suse.cz> <20160506203308.GA12506@linux.intel.com> <20160509093828.GF11897@quack2.suse.cz> <20160510152814.GQ11897@quack2.suse.cz> <20160510203003.GA5314@linux.intel.com> <20160510223937.GA10222@linux.intel.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="LQksG6bCIzRHxTLp" Cc: Jan Kara , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Dan Williams , linux-nvdimm@lists.01.org, Matthew Wilcox To: Ross Zwisler Return-path: Content-Disposition: inline In-Reply-To: <20160510223937.GA10222@linux.intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org --LQksG6bCIzRHxTLp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue 10-05-16 16:39:37, Ross Zwisler wrote: > On Tue, May 10, 2016 at 02:30:03PM -0600, Ross Zwisler wrote: > > On Tue, May 10, 2016 at 05:28:14PM +0200, Jan Kara wrote: > > > On Mon 09-05-16 11:38:28, Jan Kara wrote: > > > Somehow, I'm not able to reproduce the warnings... Anyway, I think I see > > > what's going on. Can you check whether the warning goes away when you > > > change the condition at the end of page_cache_tree_delete() to: > > > > > > if (!dax_mapping(mapping) && !workingset_node_pages(node) && > > > list_empty(&node->private_list)) { > > > > Yep, this took care of both of the issues that I reported. I'll restart my > > testing with this in my baseline, but as of this fix I don't have any more > > open testing issues. :) > > Well, looks like I spoke too soon. The two tests that were failing for me are > now passing, but I can still create what looks like a related failure using > XFS, DAX, and the two xfstests generic/231 and generic/232 run back-to-back. Hum, full xfstests run completes for me just fine. Can you reproduce the issue with the attached debug patch? Thanks! Honza -- Jan Kara SUSE Labs, CR --LQksG6bCIzRHxTLp Content-Type: text/x-patch; charset=us-ascii Content-Disposition: attachment; filename="0001-Debugging-workingset.patch" >From 8f01c60e8be5d5671b09b07a5fb647177e33293d Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 11 May 2016 11:14:11 +0200 Subject: [PATCH] Debugging workingset Signed-off-by: Jan Kara --- mm/workingset.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/mm/workingset.c b/mm/workingset.c index 8a75f8d2916a..b692fc756fda 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -12,6 +12,7 @@ #include #include #include +#include /* * Double CLOCK lists @@ -402,6 +403,7 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, node = container_of(item, struct radix_tree_node, private_list); mapping = node->private_data; + WARN_ON(dax_mapping(mapping)); /* Coming from the list, invert the lock order */ if (!spin_trylock(&mapping->tree_lock)) { @@ -418,7 +420,18 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, * no pages, so we expect to be able to remove them all and * delete and free the empty node afterwards. */ - + if (!node->count || (node->count & RADIX_TREE_COUNT_MASK)) { + printk(KERN_ERR "Wrong node->count %u.\n", node->count); + if (!mapping->host) { + printk(KERN_ERR "Node mapping has no host!\n"); + } else { + printk(KERN_ERR "Host sb %s ino %lu\n", mapping->host->i_sb->s_id, mapping->host->i_ino); + } + printk(KERN_ERR "Node dump:"); + for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) + printk(KERN_CONT " %lx", (unsigned long)node->slots[i]); + printk(KERN_CONT "\n"); + } BUG_ON(!node->count); BUG_ON(node->count & RADIX_TREE_COUNT_MASK); -- 2.6.6 --LQksG6bCIzRHxTLp-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org