On 05/04/17 14:39, Vlastimil Babka wrote: > On 04/05/2017 01:36 PM, Richard Weinberger wrote: >> Michal, >> >> Am 05.04.2017 um 13:31 schrieb Michal Hocko: >>> On Wed 05-04-17 09:47:00, Vlastimil Babka wrote: >>>> Nandsim has own functions set_memalloc() and clear_memalloc() for robust >>>> setting and clearing of PF_MEMALLOC. Replace them by the new generic helpers. >>>> No functional change. >>> >>> This one smells like an abuser. Why the hell should read/write path >>> touch memory reserves at all! >> >> Could be. Let's ask Adrian, AFAIK he wrote that code. >> Adrian, can you please clarify why nandsim needs to play with PF_MEMALLOC? > > I was thinking about it and concluded that since the simulator can be > used as a block device where reclaimed pages go to, writing the data out > is a memalloc operation. Then reading can be called as part of r-m-w > cycle, so reading as well. IIRC it was to avoid getting stuck with nandsim waiting on memory reclaim and memory reclaim waiting on nandsim.
