From: Hugh Dickins Date: Tue, 22 Sep 2009 00:02:16 +0000 (-0700) Subject: ksm: fix endless loop on oom X-Git-Tag: v2.6.32-rc1~546 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d952b79136a6c32a3f97e0628ca78340f1d5c6f9;p=pandora-kernel.git ksm: fix endless loop on oom break_ksm has been looping endlessly ignoring VM_FAULT_OOM: that should only be a problem for ksmd when a memory control group imposes limits (normally the OOM killer will kill others with an mm until it succeeds); but in general (especially for MADV_UNMERGEABLE and KSM_RUN_UNMERGE) we do need to route the error (or kill) back to the caller (or sighandling). Test signal_pending in unmerge_ksm_pages, which could be a lengthy procedure if it has to spill into swap: returning -ERESTARTSYS so that trivial signals will restart but fatals will terminate (is that right? we do different things in different places in mm, none exactly this). unmerge_and_remove_all_rmap_items was forgetting to lock when going down the mm_list: fix that. Whether it's successful or not, reset ksm_scan cursor to head; but only if it's successful, reset seqnr (shown in full_scans) - page counts will have gone down to zero. This patch leaves a significant OOM deadlock, but it's a good step on the way, and that deadlock is fixed in a subsequent patch. Signed-off-by: Hugh Dickins Acked-by: Izik Eidus Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed