On 04/24/2012 02:16 PM, KAMEZAWA Hiroyuki wrote: > (2012/04/23 17:55), Minchan Kim wrote: > >> As I test some code, I found a problem about deadlock by lockdep. >> The reason I saw the message is __vmalloc calls map_vm_area which calls >> pud/pmd_alloc without gfp_t. so although we call __vmalloc with >> GFP_ATOMIC or GFP_NOIO, it ends up allocating pages with GFP_KERNEL. >> The should be a BUG. This patch fixes it by passing gfp_to to low page >> table allocate functions. >> >> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> > > > Hmm ? vmalloc should support GFP_ATOMIC ? I'm not sure but alloc_large_system_hash already has used. And it's not specific on GFP_ATOMIC. We have to care of GFP_NOFS and GFP_NOIO to prevent deadlock on reclaim context. There are some places to use GFP_NOFS and we don't emit any warning message in case of that. > > And, do we need to change all pud_,pgd_,pmd_,pte_alloc() for users pgtables ? Maybe. -- Kind regards, Minchan Kim -- 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>