On Mon, 2010-06-07 at 13:06 +0200, Peter Zijlstra wrote: > This patch-set makes part of the mm a lot more preemptible. It converts > i_mmap_lock and anon_vma->lock to mutexes and makes mmu_gather fully > preemptible. I applied it against 2.6.35-rc2 on x86_64 machine, but kernel booting panic. Pid: 1, comm: init Not tainted 2.6.35-rc2-petermm #1 X7DW3/X7DW3 RIP: 0010:[<ffffffff8160e055>] [<ffffffff8160e055>] mutex_unlock +0x0/0x13 RSP: 0018:ffff88022fc61a78 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff88022ebd5780 RCX: 0000000000000020 RDX: 0000000000000000 RSI: 0000000000100173 RDI: 8000000000000025 RBP: 0000000000000020 R08: 00007fffffffe000 R09: 0000000000000001 R10: 0000000000000002 R11: ffffffff8128c275 R12: ffff88022e76b000 R13: 0000000000021000 R14: ffff88022fc68000 R15: 00007fff4c0e6000 FS: 0000000000000000(0000) GS:ffff8800021c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 000000022e76c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process init (pid: 1, threadinfo ffff88022fc60000, task ffff88022fc58000) Stack: ffffffff810aabac 00000000ffffefff 0000000000000000 00007fff4c107000 <0> ffff88022e76b000 00007fffffffe000 00007ffffffff000 00007fff4c106000 <0> ffffffff810c5e5a ffff88022ebd5780 ffff88022ebd5780 ffff88022ebd5780 Call Trace: [<ffffffff810aabac>] ? expand_downwards+0x149/0x15a [<ffffffff810c5e5a>] ? setup_arg_pages+0x333/0x361 [<ffffffff810c8955>] ? inode_permission+0x76/0x95 [<ffffffff810f8a19>] ? load_elf_binary+0x0/0x16c9 [<ffffffff810f8e7e>] ? load_elf_binary+0x465/0x16c9 [<ffffffff810c488a>] ? get_arg_page+0x4b/0xa4 [<ffffffff810f8a19>] ? load_elf_binary+0x0/0x16c9 [<ffffffff810c4ce4>] ? search_binary_handler+0xd4/0x26f [<ffffffff810f7a1c>] ? load_script+0x0/0x1e4 [<ffffffff810f7bea>] ? load_script+0x1ce/0x1e4 [<ffffffff810c488a>] ? get_arg_page+0x4b/0xa4 [<ffffffff810c4ce4>] ? search_binary_handler+0xd4/0x26f [<ffffffff810c6228>] ? do_execve+0x1e5/0x2b6 [<ffffffff81008d60>] ? sys_execve+0x35/0x53 [<ffffffff81003648>] ? kernel_execve+0x68/0xd0 [<ffffffff81000342>] ? init_post+0x5a/0xd4 [<ffffffff81cdf97d>] ? kernel_init+0x1e5/0x1ec [<ffffffff810035d4>] ? kernel_thread_helper+0x4/0x10 [<ffffffff81cdf798>] ? kernel_init+0x0/0x1ec [<ffffffff810035d0>] ? kernel_thread_helper+0x0/0x10 Code: 1c 24 44 89 64 24 08 48 c7 44 24 20 07 fd 04 81 48 89 44 24 28 48 89 44 24 30 e8 26 ff ff ff 48 83 c4 48 5b 41 5c 41 5d 41 5e c3 <48> c7 47 18 00 00 00 00 f0 ff 07 7f 05 e8 01 00 00 00 c3 53 48 RIP [<ffffffff8160e055>] mutex_unlock+0x0/0x13 RSP <ffff88022fc61a78> ---[ end trace dc724d36e0cd4a32 ]--- > > The main motivation was making mm_take_all_locks() preemptible, since it > appears people are nesting hundreds of spinlocks there. > > The side-effects are that can finally make mmu_gather preemptible, > something which lots of people have wanted to do for a long time. > > It also gets us anon_vma refcounting, which seems to result in a nice > cleanup of the anon_vma lifetime rules wrt KSM and compaction. > > This patch-set it build and boot-tested on x86_64 (a previous version was > also tested on Dave's Niagra2 machines, and I suppose s390 did too when > Martin provided the conversion patch for his arch). > > There are no known architectures left unconverted, although some arch code > never did see a compiler (superh and um come to mind). > > Can we move this work forwards, or is there anything people would want to > see done? > > [ The series includes Rik's latest patches to the same area for > convenience ] > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html