On Fri, Mar 11, 2011 at 9:01 PM, David Rientjes <rientjes@xxxxxxxxxx> wrote: > On Fri, 11 Mar 2011, Prasad Joshi wrote: > >> A filesystem might run into a problem while calling >> __vmalloc(GFP_NOFS) inside a lock. >> >> It is expected than __vmalloc when called with GFP_NOFS should not >> callback the filesystem code even incase of the increased memory >> pressure. But the problem is that even if we pass this flag, __vmalloc >> itself allocates memory with GFP_KERNEL. >> >> Using GFP_KERNEL allocations may go into the memory reclaim path and >> try to free memory by calling file system clear_inode/evict_inode >> function. Which might lead into deadlock. >> >> For further details >> https://bugzilla.kernel.org/show_bug.cgi?id=30702 >> http://marc.info/?l=linux-mm&m=128942194520631&w=4 >> >> The patch passes the gfp allocation flag all the way down to those >> allocating functions. >> > > You're going to run into trouble by hard-wiring __GFP_REPEAT into all of > the pte allocations because if GFP_NOFS is used then direct reclaim will > usually fail (see the comment for do_try_to_free_pages(): If the caller is > !__GFP_FS then the probability of a failure is reasonably high) and, if > it does so continuously, then the page allocator will loop forever. This > bit should probably be moved a level higher in your architecture changes > to the caller passing GFP_KERNEL. Thanks a lot for your reply. I should have seen your mail before sending 23 mails :( I will make the changes suggested by you and will resend all of the patches again. Thanks and Regards, Prasad > -- 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