On Thu, Jan 27, 2011 at 02:46:45PM +0100, Johannes Weiner wrote: > The charging code can encounter a charge size that is bigger than a > regular page in two situations: one is a batched charge to fill the > per-cpu stocks, the other is a huge page charge. > > This code is distributed over two functions, however, and only the > outer one is aware of huge pages. In case the charging fails, the > inner function will tell the outer function to retry if the charge > size is bigger than regular pages--assuming batched charging is the > only case. And the outer function will retry forever charging a huge > page. > > This patch makes sure the inner function can distinguish between batch > charging and a single huge page charge. It will only signal another > attempt if batch charging failed, and go into regular reclaim when it > is called on behalf of a huge page. > Yeah, that is exactly the case I am debugging right now. Came up with different solution: pass page_size to __mem_cgroup_do_charge() and compare csize with page_size (not CHARGE_SIZE). Not sure which solution it more correct. > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> > --- > mm/memcontrol.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 8fa4be3..17c4e36 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1847,7 +1847,7 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask, > } else > mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); > > - if (csize > PAGE_SIZE) /* change csize and retry */ > + if (csize == CHARGE_SIZE) /* retry without batching */ > return CHARGE_RETRY; > > if (!(gfp_mask & __GFP_WAIT)) > -- > 1.7.3.5 > > -- > 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 policy in Canada: sign http://dissolvethecrtc.ca/ > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Gleb. -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>