On Wed, 19 Oct 2011, Linus Torvalds wrote: > On Wed, Oct 19, 2011 at 12:43 AM, Mel Gorman <mgorman@xxxxxxx> wrote: > > > > My vote is with the migration change. While there are occasionally > > patches to make migration go faster, I don't consider it a hot path. > > mremap may be used intensively by JVMs so I'd loathe to hurt it. > > Ok, everybody seems to like that more, and it removes code rather than > adds it, so I certainly prefer it too. Pawel, can you test that other > patch (to mm/migrate.c) that Hugh posted? Instead of the mremap vma > locking patch that you already verified for your setup? > > Hugh - that one didn't have a changelog/sign-off, so if you could > write that up, and Pawel's testing is successful, I can apply it... > Looks like we have acks from both Andrea and Mel. Yes, I'm glad to have that input from Andrea and Mel, thank you. Here we go. I can't add a Tested-by since Pawel was reporting on the alternative patch, but perhaps you'll be able to add that in later. I may have read too much into Pawel's mail, but it sounded like he would have expected an eponymous find_get_pages() lockup by now, and was pleased that this patch appeared to have cured that. I've spent quite a while trying to explain find_get_pages() lockup by a missed migration entry, but I just don't see it: I don't expect this (or the alternative) patch to do anything to fix that problem. I won't mind if it magically goes away, but I expect we'll need more info from the debug patch I sent Justin a couple of days ago. Ah, I'd better send the patch separately as "[PATCH] mm: fix race between mremap and removing migration entry": Pawel's "l" makes my old alpine setup choose quoted printable when I reply to your mail. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>