Attachment 79158 Details for Bug 152099

[patch] Patch to fix lockup

InvalidateInodeSoftLockup (text/plain), 1.50 KB, created by Neil Brown on 2006-04-20 06:04:19 UTC

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Creator: Neil Brown

Created: 2006-04-20 06:04:19 UTC

Size: 1.50 KB

patch

obsolete

>Status: ok
>
>Remove softlockup from invalidate_mapping_pages.
>
>If invalidate_mapping_pages is called to invalidate a very large
>mapping (e.g. a very large block device) and if the only active page
>in that device is near the end  (or at least, at a very large  index),
>such as, say, the superblock of an md array, and if that page
>happens to be locked when invalidate_mapping_pages is called,
>then
>  pagevec_lookup will return this page and
>  as it is locked, 'next' will be incremented and pagevec_lookup
>  will be called again. and again. and again.
>  while we count from 0 upto a very large number.
>
>We should really always set 'next' to 'page->index+1' before going
>around the loop again, not just if the page isn't locked.
>
>
>Cc: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
>Signed-off-by: Neil Brown <neilb@suse.de>
>
>### Diffstat output
> ./mm/truncate.c |   10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
>diff ./mm/truncate.c~current~ ./mm/truncate.c
>--- ./mm/truncate.c~current~	2006-04-20 15:27:22.000000000 +1000
>+++ ./mm/truncate.c	2006-04-20 15:38:20.000000000 +1000
>@@ -238,13 +238,11 @@ unsigned long invalidate_mapping_pages(s
> 		for (i = 0; i < pagevec_count(&pvec); i++) {
> 			struct page *page = pvec.pages[i];
> 
>-			if (TestSetPageLocked(page)) {
>-				next++;
>+			next = page->index+1;
>+
>+			if (TestSetPageLocked(page))
> 				continue;
>-			}
>-			if (page->index > next)
>-				next = page->index;
>-			next++;
>+
> 			if (PageDirty(page) || PageWriteback(page))
> 				goto unlock;
> 			if (page_mapped(page))

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Attachments on bug 152099: 79158