Re: all processes waiting in TASK_UNINTERRUPTIBLE state

Christian Ehrhardt
2001-06-26T09:21:23Z

On Mon, Jun 25, 2001 at 12:05:14PM -0500, Jeff Dike wrote:
> abali@us.ibm.com said:
> > I am running in to a problem, seemingly a deadlock situation, where
> > almost all the processes end up in the TASK_UNINTERRUPTIBLE state.
> > All the process eventually stop responding, including login shell, no
> > screen updates, keyboard etc. Can ping and sysrq key works. I
> > traced the tasks through sysrq-t key. The processors are in the idle
> > state. Tasks all seem to get stuck in the __wait_on_page or
> > __lock_page.
>
> I've seen this under UML, Rik van Riel has seen it on a physical box, and we
> suspect that they're the same problem (i.e. mine isn't a UML-specific bug).
>
> I've done some poking at the problem, but haven't really learned anything
> except that something is locking pages and not unlocking them. Figuring out
> who that is was going to be my next step.

Could it be smbfs? The following piece of code from smb_writepage
looks like it could return with the page locked:

static int
smb_writepage(struct page *page)
{

/* .... */

/* easy case */
if (page->index < end_index)
goto do_it;
/* things got complicated... */
offset = inode->i_size & (PAGE_CACHE_SIZE-1);
/* OK, are we completely out? */
if (page->index >= end_index+1 || !offset)
return -EIO; <===== This looks bad!
do_it:
get_page(page);
err = smb_writepage_sync(inode, page, 0, offset);
SetPageUptodate(page);
UnlockPage(page);
put_page(page);
return err;
}

regards Christian

--
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