Messages in this thread Patch in this message | | | Date | Wed, 03 Aug 2011 15:01:28 -0700 | From | Greg KH <> | Subject | [068/102] mm/backing-dev.c: reset bdi min_ratio in bdi_unregister() |
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3.0-stable review patch. If anyone has any objections, please let us know.
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From: Peter Zijlstra <peterz@infradead.org>
commit ccb6108f5b0b541d3eb332c3a73e645c0f84278e upstream.
Vito said:
: The system has many usb disks coming and going day to day, with their : respective bdi's having min_ratio set to 1 when inserted. It works for : some time until eventually min_ratio can no longer be set, even when the : active set of bdi's seen in /sys/class/bdi/*/min_ratio doesn't add up to : anywhere near 100. : : This then leads to an unrelated starvation problem caused by write-heavy : fuse mounts being used atop the usb disks, a problem the min_ratio setting : at the underlying devices bdi effectively prevents.
Fix this leakage by resetting the bdi min_ratio when unregistering the BDI.
Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reported-by: Vito Caputo <lkml@pengaru.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- mm/backing-dev.c | 1 + 1 file changed, 1 insertion(+)
--- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -606,6 +606,7 @@ static void bdi_prune_sb(struct backing_ void bdi_unregister(struct backing_dev_info *bdi) { if (bdi->dev) { + bdi_set_min_ratio(bdi, 0); trace_writeback_bdi_unregister(bdi); bdi_prune_sb(bdi); del_timer_sync(&bdi->wb.wakeup_timer);
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