On Thu, Jun 18, 2015 at 08:46:39PM +0900, Sergey Senozhatsky wrote: > We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY} > pages. Put a page with higher ->inuse count first within its > ->fullness_list, which will give us better chances to fill up this > page with new objects (find_get_zspage() return ->fullness_list head > for new object allocation), so some zspages will become > ZS_ALMOST_FULL/ZS_FULL quicker. > > It performs a trivial and cheap ->inuse compare which does not slow > down zsmalloc, and in the worst case it keeps the list pages not in > any particular order, just like we do it now. > > A more expensive solution could sort fullness_list by ->inuse count. > > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> > --- > mm/zsmalloc.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c > index 7d816c2..6e2ebb6 100644 > --- a/mm/zsmalloc.c > +++ b/mm/zsmalloc.c > @@ -659,8 +659,16 @@ static void insert_zspage(struct page *page, struct size_class *class, > return; > > head = &class->fullness_list[fullness]; > - if (*head) > - list_add_tail(&page->lru, &(*head)->lru); > + if (*head) { > + /* > + * We want to see more ZS_FULL pages and less almost > + * empty/full. Put pages with higher ->inuse first. > + */ > + if (page->inuse < (*head)->inuse) > + list_add_tail(&page->lru, &(*head)->lru); > + else > + list_add(&page->lru, &(*head)->lru); > + } > > *head = page; Why do you want to always put @page in the head? How about this? diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index e8cb31c..1c5fde9 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -658,21 +658,25 @@ static void insert_zspage(struct page *page, struct size_class *class, if (fullness >= _ZS_NR_FULLNESS_GROUPS) return; + zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ? + CLASS_ALMOST_EMPTY : CLASS_ALMOST_FULL, 1); + head = &class->fullness_list[fullness]; - if (*head) { - /* - * We want to see more ZS_FULL pages and less almost - * empty/full. Put pages with higher ->inuse first. - */ - if (page->inuse < (*head)->inuse) - list_add_tail(&page->lru, &(*head)->lru); - else - list_add(&page->lru, &(*head)->lru); + if (!*head) { + *head = page; + return; } - *head = page; - zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ? - CLASS_ALMOST_EMPTY : CLASS_ALMOST_FULL, 1); + /* + * We want to see more ZS_FULL pages and less almost + * empty/full. Put pages with higher ->inuse first. + */ + list_add_tail(&page->lru, &(*head)->lru); + if (page->inuse >= (*head)->inuse) + *head = page; } /* -- 1.7.9.5 > zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ? > -- > 2.4.4 > -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>