Re: [patch] voluntary-preempt-2.6.8.1-P9

K.R. Foley
2004-08-25T03:26:39Z

Any idea what is going on here?

dmesg gives me this:

(kswapd0/32): new 305 us maximum-latency critical section.
=> started at: <get_swap_page+0x28/0x280>
=> ended at: <get_swap_page+0x96/0x280>
[<c0135dbf>] check_preempt_timing+0x19f/0x240
[<c0151bf6>] get_swap_page+0x96/0x280
[<c0151bf6>] get_swap_page+0x96/0x280
[<c0135f88>] sub_preempt_count+0x48/0x60
[<c0135f88>] sub_preempt_count+0x48/0x60
[<c0151bf6>] get_swap_page+0x96/0x280
[<c015155a>] add_to_swap+0x2a/0xd0
[<c0142a73>] shrink_list+0x4e3/0x530
[<c01413a6>] lru_add_drain+0x36/0x70
[<c0135f88>] sub_preempt_count+0x48/0x60
[<c0142bc2>] shrink_cache+0x102/0x370
[<c0135f88>] sub_preempt_count+0x48/0x60
[<c0142c26>] shrink_cache+0x166/0x370
[<c014345e>] shrink_zone+0xae/0xe0
[<c0143871>] balance_pgdat+0x1e1/0x250
[<c01439a5>] kswapd+0xc5/0xe0
[<c0117cc0>] autoremove_wake_function+0x0/0x60
[<c0106336>] ret_from_fork+0x6/0x14
[<c0117cc0>] autoremove_wake_function+0x0/0x60
[<c01438e0>] kswapd+0x0/0xe0
[<c0104505>] kernel_thread_helper+0x5/0x10

The trace actually looks like this:

preemption latency trace v1.0.2
-------------------------------
latency: 305 us, entries: 2 (2)
-----------------
| task: kswapd0/32, uid:0 nice:0 policy:0 rt_prio:0
-----------------
=> started at: get_swap_page+0x28/0x280
=> ended at: get_swap_page+0x96/0x280
=======>
00000001 0.000ms (+0.000ms): get_swap_page (add_to_swap)
00000001 0.306ms (+0.306ms): sub_preempt_count (get_swap_page)