On Mon 30-03-15 11:32:40, Dave Chinner wrote: > On Fri, Mar 27, 2015 at 11:05:09AM -0400, Johannes Weiner wrote: [...] > > GFP_NOFS sites are currently one of the sites that can deadlock inside > > the allocator, even though many of them seem to have fallback code. > > My reasoning here is that if you *have* an exit strategy for failing > > allocations that is smarter than hanging, we should probably use that. > > We already do that for allocations where we can handle failure in > GFP_NOFS conditions. It is, however, somewhat useless if we can't > tell the allocator to try really hard if we've already had a failure > and we are already in memory reclaim conditions (e.g. a shrinker > trying to clean dirty objects so they can be reclaimed). > > From that perspective, I think that this patch set aims force us > away from handling fallbacks ourselves because a) it makes GFP_NOFS > more likely to fail, and b) provides no mechanism to "try harder" > when we really need the allocation to succeed.
You can ask for this "try harder" by __GFP_HIGH flag. Would that help in your fallback case? -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
