Re: swapping and the value of /proc/sys/vm/swappiness

[Nick Piggin <piggin@cyberone.com.au>]

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Nick Piggin wrote:

>
> Thanks Ray. From looking over your old results, it appears that 
> -kswapdfix
> probably has the nicest swappiness ramp, which is probably to be 
> expected,
> as the problem that is being fixed did exist in all other kernels you 
> tested,
> but the later ones just had other aggrivating changes.
>
> The swappiness=60 weirdness might just be some obscure interaction 
> with the
> workload. If that is the case, it is probably not too important, 
> however it
> could be due to a possible oversight in my patch....
>

Here is a patch on top of the last one - if you can give it a test
some time, that would be great.

Thanks
Nick


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---

 linux-2.6-npiggin/mm/vmscan.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff -puN mm/vmscan.c~vm-no-wild-kswapd2 mm/vmscan.c
--- linux-2.6/mm/vmscan.c~vm-no-wild-kswapd2	2004-09-29 10:30:49.000000000 +1000
+++ linux-2.6-npiggin/mm/vmscan.c	2004-09-29 10:34:00.000000000 +1000
@@ -991,6 +991,7 @@ out:
 static int balance_pgdat(pg_data_t *pgdat, int nr_pages)
 {
 	int to_free = nr_pages;
+	int all_zones_ok;
 	int priority;
 	int i;
 	int total_scanned, total_reclaimed;
@@ -1013,10 +1014,11 @@ loop_again:
 	}
 
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
-		int all_zones_ok = 1;
 		int end_zone = 0;	/* Inclusive.  0 = ZONE_DMA */
 		unsigned long lru_pages = 0;
 
+		all_zones_ok = 1;
+
 		if (nr_pages == 0) {
 			/*
 			 * Scan in the highmem->dma direction for the highest
@@ -1106,7 +1108,7 @@ scan:
 		 * on zone->*_priority.
 		 */
 		if (total_reclaimed >= SWAP_CLUSTER_MAX)
-			goto loop_again;
+			break;
 	}
 out:
 	for (i = 0; i < pgdat->nr_zones; i++) {
@@ -1114,6 +1116,9 @@ out:
 
 		zone->prev_priority = zone->temp_priority;
 	}
+	if (!all_zones_ok)
+		goto loop_again;
+
 	return total_reclaimed;
 }
 

_