From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <400CB3BD.4020601@cyberone.com.au> Date: Tue, 20 Jan 2004 15:51:09 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Memory management in 2.6 Content-Type: multipart/mixed; boundary="------------060301050200030401030506" Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: Andrew Morton List-ID: This is a multi-part message in MIME format. --------------060301050200030401030506 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Hi, In the interest of helping improve 2.6 VM performance when under heavy swapping load, I'm putting together a few regression tests. If anyone has any suggestions of workloads I could use, I will try to include them, or code them up if you want a simple concept tested. Also, any suggestions of what information I should gather? loads should be runnable on about 64MB, preferably give decently repeatable results in under an hour. I'll be happy to test patches. Here is one (results are a bit wild because it was only 1 run). Nick --------------060301050200030401030506 Content-Type: text/plain; name="vm-akpm-balance-pgdat.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="vm-akpm-balance-pgdat.patch" linux-2.6-npiggin/mm/vmscan.c | 30 +++++++++++++++++++++++------- 1 files changed, 23 insertions(+), 7 deletions(-) diff -puN mm/vmscan.c~vm-akpm-balance-pgdat mm/vmscan.c --- linux-2.6/mm/vmscan.c~vm-akpm-balance-pgdat 2004-01-17 20:35:39.000000000 +1100 +++ linux-2.6-npiggin/mm/vmscan.c 2004-01-17 20:35:42.000000000 +1100 @@ -941,11 +941,12 @@ static int balance_pgdat(pg_data_t *pgda int nr_mapped = 0; int max_scan; int to_reclaim; + int reclaimed; if (zone->all_unreclaimable && priority != DEF_PRIORITY) continue; - if (nr_pages && to_free > 0) { /* Software suspend */ + if (nr_pages && nr_pages > 0) { /* Software suspend */ to_reclaim = min(to_free, SWAP_CLUSTER_MAX*8); } else { /* Zone balancing */ to_reclaim = zone->pages_high-zone->free_pages; @@ -953,28 +954,43 @@ static int balance_pgdat(pg_data_t *pgda continue; } zone->temp_priority = priority; - all_zones_ok = 0; max_scan = zone->nr_inactive >> priority; if (max_scan < to_reclaim * 2) max_scan = to_reclaim * 2; if (max_scan < SWAP_CLUSTER_MAX) max_scan = SWAP_CLUSTER_MAX; - to_free -= shrink_zone(zone, max_scan, GFP_KERNEL, + reclaimed = shrink_zone(zone, max_scan, GFP_KERNEL, to_reclaim, &nr_mapped, ps, priority); if (i < ZONE_HIGHMEM) { reclaim_state->reclaimed_slab = 0; shrink_slab(max_scan + nr_mapped, GFP_KERNEL); - to_free -= reclaim_state->reclaimed_slab; + reclaimed += reclaim_state->reclaimed_slab; } + to_free -= reclaimed; if (zone->all_unreclaimable) continue; if (zone->pages_scanned > zone->present_pages * 2) zone->all_unreclaimable = 1; + /* + * If this scan failed to reclaim `to_reclaim' or more + * pages, we're getting into trouble. Need to scan + * some more, and throttle kswapd. Note that this zone + * may now have sufficient free pages due to freeing + * activity by some other process. That's OK - we'll + * pick that info up on the next pass through the loop. + */ + if (reclaimed < to_reclaim) + all_zones_ok = 0; } - if (all_zones_ok) - break; if (to_free > 0) - blk_congestion_wait(WRITE, HZ/10); + continue; /* swsusp: need to do more work */ + if (all_zones_ok) + break; /* kswapd: all done */ + /* + * OK, kswapd is getting into trouble. Take a nap, then take + * another pass across the zones. + */ + blk_congestion_wait(WRITE, HZ/10); } for (i = 0; i < pgdat->nr_zones; i++) { _ --------------060301050200030401030506-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org