Messages in this thread | | | Date | Fri, 27 Sep 2002 22:54:54 -0700 | From | Andrew Morton <> | Subject | Re: mremap() pte allocation atomicity error |
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William Lee Irwin III wrote: > > I'm working on something else atm. > > [<c01187b3>]__might_sleep+0x43/0x47 > [<c013b6d4>]__alloc_pages+0x24/0x20c > [<c0133650>]file_read_actor+0x0/0x1b0 > [<c01131ed>]pte_alloc_one+0x41/0x104 > [<c012d05d>]pte_alloc_map+0x4d/0x210 > [<c013bc73>]get_page_cache_size+0xf/0x18 > [<c0135f38>]move_one_page+0xe8/0x328 > [<c0136061>]move_one_page+0x211/0x328 > [<c0130644>]vm_enough_memory+0x34/0xc0 > [<c01361a9>]move_page_tables+0x31/0x7c > [<c0136860>]do_mremap+0x66c/0x7ec > [<c0136a30>]sys_mremap+0x50/0x73 > [<c010748f>]syscall_call+0x7/0xb >
ooh, oww, ouch. Look at move_one_page():
src = get_one_pte_map_nested(mm, old_addr); if (src) { dst = alloc_one_pte_map(mm, new_addr); error = copy_one_pte(mm, src, dst);
get_one_pte_map_nested() does a kmap_atomic(), and then we go and call alloc_one_pte_map->pte_alloc_map->pte_alloc_one->alloc_pages() inside that kmap_atomic().
I guess that has been there since day one.
A simple fix would be to drop the atomic kmap of the source pte and take it again after the alloc_one_pte_map() call.
Can you think of a more efficient way? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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