Re: 2.5.38-mm1 dbench 512 might sleep backtrace emitted

From: Andrew Morton (
Date: Mon Sep 23 2002 - 00:31:04 EST

William Lee Irwin III wrote:
> Trace; c01175f7 <__might_sleep+27/2b>
> Trace; c0139764 <__alloc_pages+24/24c>
> Trace; f8e74698 <END_OF_CODE+38ac8334/????>
> Trace; c011300d <pte_alloc_one+41/118>
> Trace; c012b89d <pte_alloc_map+4d/214>
> Trace; c012da28 <vmtruncate+138/164>
> Trace; c0133f68 <move_one_page+e8/328>
> Trace; c0134091 <move_one_page+211/328>
> Trace; c01341d9 <move_page_tables+31/7c>
> Trace; c0134870 <do_mremap+64c/7cc>
> Trace; c0134a40 <sys_mremap+50/73>
> Trace; c010746f <syscall_call+7/b>

Well I can't immediately see any held locks on that path, can
you? Odd.

Might be best to put a breakpoint on the printk in __might_sleep(),
get some more info if it bites again.

If there _are_ no locks held in that chain then there is
something wrong with in_atomic(). So check the current
task state with `task25' and `thread25' from my .gdbinit.

set editing on
set radix 0x0a

define rmt
set remotebaud 115200
target remote /dev/ttyS0

define comm25
p ((struct thread_info *)((int)$esp & ~0x1fff))->task->comm

define task25
p ((struct thread_info *)((int)$esp & ~0x1fff))->task

define thread25
p ((struct thread_info *)((int)$esp & ~0x1fff))

define reboot
        maintenance packet r

define page_states
printf "Dirty: %dK\n", (page_states[0].nr_dirty + page_states[1].nr_dirty + page_states[2].nr_dirty + page_states[3].nr_dirty) * 4
printf "Writeback: %dK\n", (page_states[0].nr_writeback + page_states[1].nr_writeback + page_states[2].nr_writeback + page_states[3].nr_writeback) * 4
printf "Pagecache: %dK\n", (page_states[0].nr_pagecache + page_states[1].nr_pagecache + page_states[2].nr_pagecache + page_states[3].nr_pagecache) * 4
printf "Page Table Pages: %d\n", (page_states[0].nr_page_table_pages + page_states[1].nr_page_table_pages + page_states[2].nr_page_table_pages + page_states[3].nr_page_table_pages) * 4
printf "nr_reverse_maps: %d\n", page_states[0].nr_reverse_maps + page_states[1].nr_reverse_maps + page_states[2].nr_reverse_maps + page_states[3].nr_reverse_maps

define offsetof
        set $off = &(((struct $arg0 *)0)->$arg1)
        printf "%d 0x%x\n", $off, $off

# list_entry list type member
define list_entry
        set $off = (int)&(((struct $arg1 *)0)->$arg2)
        set $addr = (int)$arg0
        set $res = $addr - $off
        printf "0x%x\n", $res
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This archive was generated by hypermail 2b29 : Mon Sep 23 2002 - 22:00:38 EST