Too much free memory (not used for FS cache)

Too much free memory (not used for FS cache)

[Jiri Slaby]

Hi,

since today's -next (20120315), the MM/VFS system is very sluggish.
Especially when committing, diffing and similar with git. I still have
2G of 6G of memory free. But with each commit I have to wait for git to
fetch all data from disk.

I'm using ext4 on a raid for the partition with git kernel repository if
that matters.

Any idea what that could be?

nr_free_pages 555469
nr_inactive_anon 16787
nr_active_anon 414439
nr_inactive_file 315585
nr_active_file 137446
nr_unevictable 0
nr_mlock 0
nr_anon_pages 277729
nr_mapped 95971
nr_file_pages 524644
nr_dirty 11
nr_writeback 0
nr_slab_reclaimable 35548
nr_slab_unreclaimable 7450
nr_page_table_pages 11493
nr_kernel_stack 464
nr_unstable 0
nr_bounce 0
nr_vmscan_write 0
nr_vmscan_immediate_reclaim 0
nr_writeback_temp 0
nr_isolated_anon 0
nr_isolated_file 0
nr_shmem 71614
nr_dirtied 1165398
nr_written 1147058
nr_anon_transparent_hugepages 160
nr_dirty_threshold 97608
nr_dirty_background_threshold 48804
pgpgin 2446144
pgpgout 4844237
pswpin 0
pswpout 0
pgalloc_dma 0
pgalloc_dma32 21764611
pgalloc_normal 38307626
pgalloc_movable 0
pgfree 60640227
pgactivate 913299
pgdeactivate 109336
pgfault 51012433
pgmajfault 8476
pgrefill_dma 0
pgrefill_dma32 79208
pgrefill_normal 41244
pgrefill_movable 0
pgsteal_dma 0
pgsteal_dma32 162966
pgsteal_normal 185373
pgsteal_movable 0
pgscan_kswapd_dma 0
pgscan_kswapd_dma32 162559
pgscan_kswapd_normal 215360
pgscan_kswapd_movable 0
pgscan_direct_dma 0
pgscan_direct_dma32 1624
pgscan_direct_normal 3927
pgscan_direct_movable 0
pginodesteal 4
slabs_scanned 102400
kswapd_steal 342881
kswapd_inodesteal 756
kswapd_low_wmark_hit_quickly 0
kswapd_high_wmark_hit_quickly 119
kswapd_skip_congestion_wait 0
pageoutrun 3493
allocstall 5
pgrotated 240
compact_blocks_moved 432
compact_pages_moved 10699
compact_pagemigrate_failed 0
compact_stall 14
compact_fail 5
compact_success 9
htlb_buddy_alloc_success 0
htlb_buddy_alloc_fail 0
unevictable_pgs_culled 327
unevictable_pgs_scanned 0
unevictable_pgs_rescued 2618
unevictable_pgs_mlocked 2618
unevictable_pgs_munlocked 2618
unevictable_pgs_cleared 0
unevictable_pgs_stranded 0
unevictable_pgs_mlockfreed 0
thp_fault_alloc 13147
thp_fault_fallback 0
thp_collapse_alloc 3543
thp_collapse_alloc_failed 0
thp_split 183

thanks,
-- 
js
suse labs

Re: Too much free memory (not used for FS cache)

[Jiri Slaby]

On 03/15/2012 09:09 PM, Jiri Slaby wrote:
> Hi,
> 
> since today's -next (20120315), the MM/VFS system is very sluggish.
> Especially when committing, diffing and similar with git. I still have
> 2G of 6G of memory free. But with each commit I have to wait for git to
> fetch all data from disk.
> 
> I'm using ext4 on a raid for the partition with git kernel repository if
> that matters.
> 
> Any idea what that could be?

Please ignore this. It's not as easy as that. It doesn't wait for IO and
needs more investigation...

> nr_free_pages 555469
> nr_inactive_anon 16787
> nr_active_anon 414439
> nr_inactive_file 315585
> nr_active_file 137446
> nr_unevictable 0
> nr_mlock 0
> nr_anon_pages 277729
> nr_mapped 95971
> nr_file_pages 524644
> nr_dirty 11
> nr_writeback 0
> nr_slab_reclaimable 35548
> nr_slab_unreclaimable 7450
> nr_page_table_pages 11493
> nr_kernel_stack 464
> nr_unstable 0
> nr_bounce 0
> nr_vmscan_write 0
> nr_vmscan_immediate_reclaim 0
> nr_writeback_temp 0
> nr_isolated_anon 0
> nr_isolated_file 0
> nr_shmem 71614
> nr_dirtied 1165398
> nr_written 1147058
> nr_anon_transparent_hugepages 160
> nr_dirty_threshold 97608
> nr_dirty_background_threshold 48804
> pgpgin 2446144
> pgpgout 4844237
> pswpin 0
> pswpout 0
> pgalloc_dma 0
> pgalloc_dma32 21764611
> pgalloc_normal 38307626
> pgalloc_movable 0
> pgfree 60640227
> pgactivate 913299
> pgdeactivate 109336
> pgfault 51012433
> pgmajfault 8476
> pgrefill_dma 0
> pgrefill_dma32 79208
> pgrefill_normal 41244
> pgrefill_movable 0
> pgsteal_dma 0
> pgsteal_dma32 162966
> pgsteal_normal 185373
> pgsteal_movable 0
> pgscan_kswapd_dma 0
> pgscan_kswapd_dma32 162559
> pgscan_kswapd_normal 215360
> pgscan_kswapd_movable 0
> pgscan_direct_dma 0
> pgscan_direct_dma32 1624
> pgscan_direct_normal 3927
> pgscan_direct_movable 0
> pginodesteal 4
> slabs_scanned 102400
> kswapd_steal 342881
> kswapd_inodesteal 756
> kswapd_low_wmark_hit_quickly 0
> kswapd_high_wmark_hit_quickly 119
> kswapd_skip_congestion_wait 0
> pageoutrun 3493
> allocstall 5
> pgrotated 240
> compact_blocks_moved 432
> compact_pages_moved 10699
> compact_pagemigrate_failed 0
> compact_stall 14
> compact_fail 5
> compact_success 9
> htlb_buddy_alloc_success 0
> htlb_buddy_alloc_fail 0
> unevictable_pgs_culled 327
> unevictable_pgs_scanned 0
> unevictable_pgs_rescued 2618
> unevictable_pgs_mlocked 2618
> unevictable_pgs_munlocked 2618
> unevictable_pgs_cleared 0
> unevictable_pgs_stranded 0
> unevictable_pgs_mlockfreed 0
> thp_fault_alloc 13147
> thp_fault_fallback 0
> thp_collapse_alloc 3543
> thp_collapse_alloc_failed 0
> thp_split 183
> 
> thanks,


-- 
js
suse labs

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Re: Too much free memory (not used for FS cache)

[Andrew Morton]

On Thu, 15 Mar 2012 21:09:44 +0100
Jiri Slaby <jslaby@suse.cz> wrote:

> since today's -next (20120315), the MM/VFS system is very sluggish.
> Especially when committing, diffing and similar with git. I still have
> 2G of 6G of memory free. But with each commit I have to wait for git to
> fetch all data from disk.
> 
> I'm using ext4 on a raid for the partition with git kernel repository if
> that matters.
> 
> Any idea what that could be?

The last mm->next update was March 5th so it won't be from stuff in the
-mm queue.

Are you sure it's reclaim-related?  Perhaps something in the IO system
got slow?




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