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Message-ID: <20090211003715.GB6422@barrios-desktop>
Date: Wed, 11 Feb 2009 09:37:15 +0900
From: MinChan Kim <minchan.kim@...il.com>
To: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
Cc: Johannes Weiner <hannes@...xchg.org>,
Rik van Riel <riel@...hat.com>,
"Rafael J. Wysocki" <rjw@...k.pl>,
William Lee Irwin III <wli@...ementarian.org>,
Andrew Morton <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH] shrink_all_memory() use sc.nr_reclaimed
On Wed, Feb 11, 2009 at 05:41:21AM +0900, KOSAKI Motohiro wrote:
> >> {
> >> struct zone *zone;
> >> - unsigned long nr_to_scan, ret = 0;
> >> + unsigned long nr_to_scan;
> >> enum lru_list l;
> >
> > Basing it on swsusp-clean-up-shrink_all_zones.patch probably makes it
> > easier for Andrew to pick it up.
>
> ok, thanks.
>
> >> reclaim_state.reclaimed_slab = 0;
> >> - shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
> >> - ret += reclaim_state.reclaimed_slab;
> >> - } while (ret < nr_pages && reclaim_state.reclaimed_slab > 0);
> >> + shrink_slab(nr_pages, sc.gfp_mask,
> >> + global_lru_pages());
> >> + sc.nr_reclaimed += reclaim_state.reclaimed_slab;
> >> + } while (sc.nr_reclaimed < nr_pages &&
> >> + reclaim_state.reclaimed_slab > 0);
> >
> > :(
> >
> > Is this really an improvement? `ret' is better to read than
> > `sc.nr_reclaimed'.
>
> I know it's debetable thing.
> but I still think code consistency is important than variable name preference.
How about this ?
I followed do_try_to_free_pages coding style.
It use both 'sc->nr_reclaimed' and 'ret'.
It can support code consistency and readability.
So, I think it would be better.
If you don't mind, I will resend with your sign-off.
Signed-off-by: MinChan Kim <minchan.kim@...il.com>
---
mm/vmscan.c | 43 +++++++++++++++++++++++++------------------
1 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9a27c44..989062a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2048,16 +2048,16 @@ unsigned long global_lru_pages(void)
#ifdef CONFIG_PM
/*
* Helper function for shrink_all_memory(). Tries to reclaim 'nr_pages' pages
- * from LRU lists system-wide, for given pass and priority, and returns the
- * number of reclaimed pages
+ * from LRU lists system-wide, for given pass and priority.
*
* For pass > 3 we also try to shrink the LRU lists that contain a few pages
*/
-static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
+static void shrink_all_zones(unsigned long nr_pages, int prio,
int pass, struct scan_control *sc)
{
struct zone *zone;
unsigned long nr_to_scan, ret = 0;
+ unsigned long nr_reclaimed = sc->nr_reclaimed;
enum lru_list l;
for_each_zone(zone) {
@@ -2082,15 +2082,14 @@ static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
nr_to_scan = min(nr_pages,
zone_page_state(zone,
NR_LRU_BASE + l));
- ret += shrink_list(l, nr_to_scan, zone,
+ nr_reclaimed += shrink_list(l, nr_to_scan, zone,
sc, prio);
- if (ret >= nr_pages)
- return ret;
- }
+ if (nr_reclaimed >= nr_pages)
+ break;
}
}
- return ret;
+ sc->nr_reclaimed = nr_reclaimed;
}
/*
@@ -2127,9 +2126,11 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
if (!reclaim_state.reclaimed_slab)
break;
- ret += reclaim_state.reclaimed_slab;
- if (ret >= nr_pages)
+ sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+ if (sc.nr_reclaimed >= nr_pages) {
+ ret = sc.nr_reclaimed;
goto out;
+ }
nr_slab -= reclaim_state.reclaimed_slab;
}
@@ -2152,19 +2153,23 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
}
for (prio = DEF_PRIORITY; prio >= 0; prio--) {
- unsigned long nr_to_scan = nr_pages - ret;
+ unsigned long nr_to_scan = nr_pages - sc.nr_reclaimed;
sc.nr_scanned = 0;
- ret += shrink_all_zones(nr_to_scan, prio, pass, &sc);
- if (ret >= nr_pages)
+ shrink_all_zones(nr_to_scan, prio, pass, &sc);
+ if (sc.nr_reclaimed >= nr_pages) {
+ ret = sc.nr_reclaimed;
goto out;
+ }
reclaim_state.reclaimed_slab = 0;
shrink_slab(sc.nr_scanned, sc.gfp_mask,
global_lru_pages());
- ret += reclaim_state.reclaimed_slab;
- if (ret >= nr_pages)
+ sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+ if (sc.nr_reclaimed >= nr_pages) {
+ ret = sc.nr_reclaimed;
goto out;
+ }
if (sc.nr_scanned && prio < DEF_PRIORITY - 2)
congestion_wait(WRITE, HZ / 10);
@@ -2175,14 +2180,16 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
* If ret = 0, we could not shrink LRUs, but there may be something
* in slab caches
*/
- if (!ret) {
+ if (!sc.nr_reclaimed) {
do {
reclaim_state.reclaimed_slab = 0;
shrink_slab(nr_pages, sc.gfp_mask, global_lru_pages());
- ret += reclaim_state.reclaimed_slab;
- } while (ret < nr_pages && reclaim_state.reclaimed_slab > 0);
+ sc.nr_reclaimed += reclaim_state.reclaimed_slab;
+ } while (sc.nr_reclaimed < nr_pages && reclaim_state.reclaimed_slab > 0);
}
+ ret = sc.nr_reclaimed;
+
out:
current->reclaim_state = NULL;
--
1.5.4.3
--
Kinds Regards
MinChan Kim
--
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