Commit d2c5e30c9a1420902262aa923794d2ae4e0bc391
("[PATCH] zoned vm counters: conversion of nr_bounce to per zone counter")
convert statistic of nr_bounce to per zone and one global value in vm_stat,
but it call inc_|dec_zone_page_state on different pages, then different
zones, and cause us to get unexpected value of NR_BOUNCE.
Below is the result on my machine:
Mar 2 09:26:08 udknight kernel: [144766.778265] Mem-Info:
Mar 2 09:26:08 udknight kernel: [144766.778266] DMA per-cpu:
Mar 2 09:26:08 udknight kernel: [144766.778268] CPU 0: hi: 0, btch: 1 usd: 0
Mar 2 09:26:08 udknight kernel: [144766.778269] CPU 1: hi: 0, btch: 1 usd: 0
Mar 2 09:26:08 udknight kernel: [144766.778270] Normal per-cpu:
Mar 2 09:26:08 udknight kernel: [144766.778271] CPU 0: hi: 186, btch: 31 usd: 0
Mar 2 09:26:08 udknight kernel: [144766.778273] CPU 1: hi: 186, btch: 31 usd: 0
Mar 2 09:26:08 udknight kernel: [144766.778274] HighMem per-cpu:
Mar 2 09:26:08 udknight kernel: [144766.778275] CPU 0: hi: 186, btch: 31 usd: 0
Mar 2 09:26:08 udknight kernel: [144766.778276] CPU 1: hi: 186, btch: 31 usd: 0
Mar 2 09:26:08 udknight kernel: [144766.778279] active_anon:46926 inactive_anon:287406 isolated_anon:0
Mar 2 09:26:08 udknight kernel: [144766.778279] active_file:105085 inactive_file:139432 isolated_file:0
Mar 2 09:26:08 udknight kernel: [144766.778279] unevictable:653 dirty:0 writeback:0 unstable:0
Mar 2 09:26:08 udknight kernel: [144766.778279] free:178957 slab_reclaimable:6419 slab_unreclaimable:9966
Mar 2 09:26:08 udknight kernel: [144766.778279] mapped:4426 shmem:305277 pagetables:784 bounce:0
Mar 2 09:26:08 udknight kernel: [144766.778279] free_cma:0
Mar 2 09:26:08 udknight kernel: [144766.778286] DMA free:3324kB min:68kB low:84kB high:100kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15976kB managed:15900kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
Mar 2 09:26:08 udknight kernel: [144766.778287] lowmem_reserve[]: 0 822 3754 3754
Mar 2 09:26:08 udknight kernel: [144766.778293] Normal free:26828kB min:3632kB low:4540kB high:5448kB active_anon:4872kB inactive_anon:68kB active_file:1796kB inactive_file:1796kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:892920kB managed:842560kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:4144kB slab_reclaimable:25676kB slab_unreclaimable:39864kB kernel_stack:1944kB pagetables:3136kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:2412612 all_unreclaimable? yes
Mar 2 09:26:08 udknight kernel: [144766.778294] lowmem_reserve[]: 0 0 23451 23451
Mar 2 09:26:08 udknight kernel: [144766.778299] HighMem free:685676kB min:512kB low:3748kB high:6984kB active_anon:182832kB inactive_anon:1149556kB active_file:418544kB inactive_file:555932kB unevictable:2612kB isolated(anon):0kB isolated(file):0kB present:3001732kB managed:3001732kB mlocked:0kB dirty:0kB writeback:0kB mapped:17704kB shmem:1216964kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:75771152kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
Mar 2 09:26:08 udknight kernel: [144766.778300] lowmem_reserve[]: 0 0 0 0
You can see bounce:75771152kB for HighMem, but bounce:0 for lowmem and global.
This patch fix it.
Signed-off-by: Wang YanQing <udknight@xxxxxxxxx>
---
Changes
v1-v2: fix comment issue reported by Leon Romanovsky
block/bounce.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/bounce.c b/block/bounce.c
index ab21ba2..ed9dd80 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -221,8 +221,8 @@ bounce:
if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force)
continue;
- inc_zone_page_state(to->bv_page, NR_BOUNCE);
to->bv_page = mempool_alloc(pool, q->bounce_gfp);
+ inc_zone_page_state(to->bv_page, NR_BOUNCE);
if (rw == WRITE) {
char *vto, *vfrom;
--
1.8.5.6.2.g3d8a54e.dirty
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