On Sat, May 28, 2011 at 3:02 PM, Hugh Dickins <hughd@xxxxxxxxxx> wrote: > > But I'm replying before I've given it enough thought, > mainly to let you know that I am back on it now. So I applied your other two patches as obvious, but not this one. I'm wondering - wouldn't it be nicer to just re-check (after getting the anon_vma lock) that page->mapping still matches anon_mapping? That said, I do agree with the "anon_vma_root" part of your patch. I just think you mixed up two independent issues with it: the fact that we may be unlocking a new root, and the precise check used to determine whether the anon_vma might have changed. So my gut feeling is that we should do the "anon_vma" root thing independently as a fix for the "maybe anon_vma->root changed" issue, and then as a separate patch decide on how to check whether anon_vma is still valid. Hmm? Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx 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>