Messages in this thread | ![/](/images/icornerl.gif) | | From | Nick Piggin <> | Subject | Re: [BUG] Lockless patches cause hardlock under heavy IO | Date | Thu, 19 Jun 2008 18:19:31 +1000 |
| |
On Thursday 19 June 2008 18:12, Peter Zijlstra wrote: > On Wed, 2008-06-18 at 17:15 -0400, Ryan Hope wrote: > > I applied the following patches from 2.6-26-rc5-mm3 to 2.6.26-rc6 and > > they caused a hardlock under heavy IO: > > What kind of machine, how much memory, how many spindles, what > filesystem and what is heavy load? > > Furthermore, try the NMI watchdog with serial/net-console to capture its > output.
Good suggestions. A trace would be really helpful.
As Arjan suggested, debug options especially CONFIG_DEBUG_VM would be a good idea to turn on if you haven't already.
BTW. what was the reason for applying those patches? Did you hit the problem with -mm also, and hope to narrow it down?
> > x86-implement-pte_special.patch > > mm-introduce-get_user_pages_fast.patch > > mm-introduce-get_user_pages_fast-fix.patch > > mm-introduce-get_user_pages_fast-checkpatch-fixes.patch > > x86-lockless-get_user_pages_fast.patch > > x86-lockless-get_user_pages_fast-checkpatch-fixes.patch > > x86-lockless-get_user_pages_fast-fix.patch > > x86-lockless-get_user_pages_fast-fix-2.patch > > x86-lockless-get_user_pages_fast-fix-2-fix-fix.patch > > x86-lockless-get_user_pages_fast-fix-warning.patch > > dio-use-get_user_pages_fast.patch > > splice-use-get_user_pages_fast.patch > > x86-support-1gb-hugepages-with-get_user_pages_lockless.patch > > # > > mm-readahead-scan-lockless.patch > > radix-tree-add-gang_lookup_slot-gang_lookup_slot_tag.patch > > #mm-speculative-page-references.patch: clameter saw bustage > > mm-speculative-page-references.patch > > mm-speculative-page-references-fix.patch > > mm-speculative-page-references-fix-fix.patch > > mm-speculative-page-references-hugh-fix3.patch > > mm-lockless-pagecache.patch > > mm-spinlock-tree_lock.patch > > powerpc-implement-pte_special.patch > > > > I am on an x86_64. I dont know what other info you need...
Can you isolate it to one of the two groups of patches? I suspect it might be the latter so you might try that first -- this version of speculative page references is very nice in theory but it is a little more complex to implement the slowpaths so it could be an error there.
| ![\](/images/icornerr.gif) |