* Ying Han <yinghan@xxxxxxxxxx> [2011-04-28 15:37:04]: > We recently added the change in global background reclaim which counts the > return value of soft_limit reclaim. Now this patch adds the similar logic > on global direct reclaim. > Sorry, I missed much of that discussion, I was away. I'll try and catch up with them soon. > We should skip scanning global LRU on shrink_zone if soft_limit reclaim does > enough work. This is the first step where we start with counting the nr_scanned > and nr_reclaimed from soft_limit reclaim into global scan_control. > > The patch is based on mmotm-04-14 and i triggered kernel BUG at mm/vmscan.c:1058! > > [ 938.242033] kernel BUG at mm/vmscan.c:1058! > [ 938.242033] invalid opcode: 0000 [#1] SMP· > [ 938.242033] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/device > [ 938.242033] Pid: 546, comm: kswapd0 Tainted: G W 2.6.39-smp-direct_reclaim > [ 938.242033] RIP: 0010:[<ffffffff810ed174>] [<ffffffff810ed174>] isolate_pages_global+0x18c/0x34f > [ 938.242033] RSP: 0018:ffff88082f83bb50 EFLAGS: 00010082 > [ 938.242033] RAX: 00000000ffffffea RBX: ffff88082f83bc90 RCX: 0000000000000401 > [ 938.242033] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea001ca653e8 > [ 938.242033] RBP: ffff88082f83bc20 R08: 0000000000000000 R09: ffff88085ffb6e00 > [ 938.242033] R10: ffff88085ffb73d0 R11: ffff88085ffb6e00 R12: ffff88085ffb6e00 > [ 938.242033] R13: ffffea001ca65410 R14: 0000000000000001 R15: ffffea001ca653e8 > [ 938.242033] FS: 0000000000000000(0000) GS:ffff88085fd00000(0000) knlGS:0000000000000000 > [ 938.242033] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 938.242033] CR2: 00007f5c3405c320 CR3: 0000000001803000 CR4: 00000000000006e0 > [ 938.242033] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 938.242033] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > [ 938.242033] Process kswapd0 (pid: 546, threadinfo ffff88082f83a000, task ffff88082fe52080) > [ 938.242033] Stack: > [ 938.242033] ffff88085ffb6e00 ffffea0000000002 0000000000000021 0000000000000000 > [ 938.242033] 0000000000000000 ffff88082f83bcb8 ffffea00108eec80 ffffea00108eecb8 > [ 938.242033] ffffea00108eecf0 0000000000000004 fffffffffffffffc 0000000000000020 > [ 938.242033] Call Trace: > [ 938.242033] [<ffffffff810ee8a5>] shrink_inactive_list+0x185/0x418 > [ 938.242033] [<ffffffff810366cc>] ? __switch_to+0xea/0x212 > [ 938.242033] [<ffffffff810e8b35>] ? determine_dirtyable_memory+0x1a/0x2c > [ 938.242033] [<ffffffff810ef19b>] shrink_zone+0x380/0x44d > [ 938.242033] [<ffffffff810e5188>] ? zone_watermark_ok_safe+0xa1/0xae > [ 938.242033] [<ffffffff810efbd8>] kswapd+0x41b/0x76b > [ 938.242033] [<ffffffff810ef7bd>] ? zone_reclaim+0x2fb/0x2fb > [ 938.242033] [<ffffffff81088569>] kthread+0x82/0x8a > [ 938.242033] [<ffffffff8141b0d4>] kernel_thread_helper+0x4/0x10 > [ 938.242033] [<ffffffff810884e7>] ? kthread_worker_fn+0x112/0x112 > [ 938.242033] [<ffffffff8141b0d0>] ? gs_change+0xb/0xb What is gs_change()? > > Thank you Minchan for the pointer. I reverted the following commit and I > haven't seen the problem with the same operation. I haven't looked deeply > on the patch yet, but figured it would be a good idea to post the dump. > The dump looks not directly related to this patchset, but ppl can use it to > reproduce the problem. > > commit 278df9f451dc71dcd002246be48358a473504ad0 > Author: Minchan Kim <minchan.kim@xxxxxxxxx> > Date: Tue Mar 22 16:32:54 2011 -0700 > > mm: reclaim invalidated page ASAP > > How to reproduce it, On my 32G of machine > 1. I create two memcgs and set their hard_limit and soft_limit: > $echo 20g >A/memory.limit_in_bytes > $echo 20g >B/memory.limit_in_bytes > $echo 3g >A/memory.soft_limit_in_bytes > $echo 3g >B/memory.soft_limit_in_bytes > > 2. Reading a 20g file on each container > $echo $$ >A/tasks > $cat /export/hdc3/dd_A/tf0 > /dev/zero > > $echo $$ >B/tasks > $cat /export/hdc3/dd_B/tf0 > /dev/zero > > 3. Add memory pressure by allocating anon + mlock. And trigger global > reclaim. > I am sorry, but the summary leaves me confused about the patchset. You mentioned adding memcg scan and reclaim, but then quickly shift focus to the stacktrace. -- Three Cheers, Balbir -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>