On Mon, 9 Apr 2012 12:42:04 -0700 Ying Han <yinghan@xxxxxxxxxx> wrote: > This reverts commit c38446cc65e1f2b3eb8630c53943b94c4f65f670. > > Before the commit, the code makes senses to me but not after the commit. The > "nr_reclaimed" is the number of pages reclaimed by scanning through the memcg's > lru lists. The "nr_to_reclaim" is the target value for the whole function. For > example, we like to early break the reclaim if reclaimed 32 pages under direct > reclaim (not DEF_PRIORITY). > > After the reverted commit, the target "nr_to_reclaim" is decremented each time > by "nr_reclaimed" but we still use it to compare the "nr_reclaimed". It just > doesn't make sense to me... > > Signed-off-by: Ying Han <yinghan@xxxxxxxxxx> > --- > mm/vmscan.c | 7 +------ > 1 files changed, 1 insertions(+), 6 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 33c332b..1a51868 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2107,12 +2107,7 @@ restart: > * with multiple processes reclaiming pages, the total > * freeing target can get unreasonably large. > */ > - if (nr_reclaimed >= nr_to_reclaim) > - nr_to_reclaim = 0; > - else > - nr_to_reclaim -= nr_reclaimed; > - > - if (!nr_to_reclaim && priority < DEF_PRIORITY) > + if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY) > break; > } > blk_finish_plug(&plug); This code is all within a loop: the "goto restart" thing. We reset nr_reclaimed to zero each time around that loop. nr_to_reclaim is (or rather, was) constant throughout the entire function. Comparing nr_reclaimed (whcih is reset each time around the loop) to nr_to_reclaim made no sense. I think the code as it stands is ugly. It would be better to make nr_to_reclaim a const and to add another local total_reclaimed, and compare that with nr_to_reclaim. Or just stop resetting nr_reclaimed each time around the loop. -- 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>