On Tue, Oct 18, 2016 at 08:56:07AM +0200, Christoph Hellwig wrote: > This is how everyone seems to already use them, but let's make that > explicit. Ah, found an exception, vmapped stacks: [ 696.928541] BUG: sleeping function called from invalid context at mm/vmalloc.c:615 [ 696.928576] in_atomic(): 1, irqs_disabled(): 0, pid: 30521, name: bash [ 696.928590] 1 lock held by bash/30521: [ 696.928600] #0: [ 696.928606] (vmap_area_lock[ 696.928619] ){+.+...}, at: [ 696.928640] [<ffffffff8115f0cf>] __purge_vmap_area_lazy+0x30f/0x370 [ 696.928656] CPU: 0 PID: 30521 Comm: bash Tainted: G W 4.9.0-rc1+ #124 [ 696.928672] Hardware name: / , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015 [ 696.928690] ffffc900070f7c70 ffffffff812be1f5 ffff8802750b6680 ffffffff819650a6 [ 696.928717] ffffc900070f7c98 ffffffff810a3216 0000000000004001 ffff8802726e16c0 [ 696.928743] ffff8802726e19a0 ffffc900070f7d08 ffffffff8115f0f3 ffff8802750b6680 [ 696.928768] Call Trace: [ 696.928782] [<ffffffff812be1f5>] dump_stack+0x68/0x93 [ 696.928796] [<ffffffff810a3216>] ___might_sleep+0x166/0x220 [ 696.928809] [<ffffffff8115f0f3>] __purge_vmap_area_lazy+0x333/0x370 [ 696.928823] [<ffffffff8115ea68>] ? vunmap_page_range+0x1e8/0x350 [ 696.928837] [<ffffffff8115f1b3>] free_vmap_area_noflush+0x83/0x90 [ 696.928850] [<ffffffff81160931>] remove_vm_area+0x71/0xb0 [ 696.928863] [<ffffffff81160999>] __vunmap+0x29/0xf0 [ 696.928875] [<ffffffff81160ab9>] vfree+0x29/0x70 [ 696.928888] [<ffffffff81071746>] put_task_stack+0x76/0x120 [ 696.928901] [<ffffffff8109a943>] finish_task_switch+0x163/0x1e0 [ 696.928914] [<ffffffff8109a845>] ? finish_task_switch+0x65/0x1e0 [ 696.928928] [<ffffffff816125f5>] __schedule+0x1f5/0x7c0 [ 696.928940] [<ffffffff81612c28>] schedule+0x38/0x90 [ 696.928953] [<ffffffff810787b1>] do_wait+0x1d1/0x200 [ 696.928966] [<ffffffff810799b1>] SyS_wait4+0x61/0xc0 [ 696.928979] [<ffffffff81076e50>] ? task_stopped_code+0x50/0x50 [ 696.928992] [<ffffffff81618e6e>] entry_SYSCALL_64_fastpath+0x1c/0xb1 [This was triggered by earlier patch to remove the serialisation and add cond_resched_lock(&vmap_area_lock)] -Chris -- Chris Wilson, Intel Open Source Technology Centre -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>