lkml.org 
[lkml]   [2013]   [May]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: [GIT PULL] SLAB changes for v3.10
    Date
    [ Sorry if I break the threading on this, I had to pull it off gmane ]

    On Tue, 7 May 2013, Tony Lindgren wrote:
    > OK got it narrowed down to CONFIG_DEBUG_SPINLOCK=y causing the problem
    > with commit 8a965b3b. Ain't nothing like bisecting and booting and then
    > diffing .config files on top of that.

    I'm unable to boot with slab on current Linus -master, and bisected it
    down almost as far as Tony did before trying SLUB and then finding this
    thread. My box is a standard x86-64, nothing exciting and spinlock
    debugging isn't on.

    A few printks stuffed into Christoph's code:

    cache ffff88047f000080 at index 5
    creating slab cache at 6
    create special cache #1 (this is kmalloc_caches[1])
    cache ffff88047f0001c0 at index 7
    creating slab cache at 8
    creating slab cache at 9
    creating slab cache at 10
    ... more get created

    Pulling this into the code from commit 8a965b3b:

    for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
    if (!kmalloc_caches[i]) {
    kmalloc_caches[i] = create_kmalloc_cache(NULL,
    1 << i, flags);

    /*
    * Caches that are not of the two-to-the-power-of size.
    * These have to be created immediately after the
    * earlier power of two caches
    */
    if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
    kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);

    if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
    kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
    }
    }

    kmalloc_caches[7] was not null, and so kmalloc_caches[2] was never
    created.

    I get this oops (with early printk on)

    ------------[ cut here ]------------
    kernel BUG at mm/slab.c:1635!
    invalid opcode: 0000 [#1] PREEMPT SMP
    Modules linked in:
    CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.9.0-josef+ #920
    Hardware name: Supermicro X9SRE/X9SRE-3F/X9SRi/X9SRi-3F/X9SRE/X9SRE-3F/X9SRi/X9SRi-3F, BIOS 1.0a 03/06/2012
    task: ffffffff8196a410 ti: ffffffff8195a000 task.ti: ffffffff8195a000
    RIP: 0010:[<ffffffff81a49c9d>] [<ffffffff81a49c9d>] kmem_cache_init_late+0x40/0x7d
    RSP: 0000:ffffffff8195bf78 EFLAGS: 00010282
    RAX: 00000000fffffff4 RBX: ffff88047f006480 RCX: 000000000000ff31
    RDX: 000000000000000e RSI: 0000000000000046 RDI: ffffffff81baf238
    RBP: ffffffff8195bf80 R08: 0000000000000400 R09: 0000000000000000
    R10: 0000000000002fa4 R11: 0000000000000000 R12: ffffffff81ab58d0
    R13: ffffffff81abd2c0 R14: ffff88047ffaf0c0 R15: 0000000000000000
    FS: 0000000000000000(0000) GS:ffff88047fc00000(0000) knlGS:0000000000000000
    CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffff88047ffff000 CR3: 0000000001965000 CR4: 00000000000406b0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Stack:
    ffffffffffffffff ffffffff8195bfc0 ffffffff81a25b64 ffffffff81a2573d
    ffffffff81abd2c0 0000000000003000 0000000000000000 0000000000000000
    0000000000000000 ffffffff8195bfd0 ffffffff81a2547f ffffffff8195bfe8
    Call Trace:
    [<ffffffff81a25b64>] start_kernel+0x235/0x394
    [<ffffffff81a2573d>] ? repair_env_string+0x58/0x58
    [<ffffffff81a2547f>] x86_64_start_reservations+0x2a/0x2c
    [<ffffffff81a25548>] x86_64_start_kernel+0xc7/0xca
    Code: 53 e8 40 57 bd ff 48 8b 05 21 f2 f4 ff 48 8d 58 a8 48 8d 43 58 48 3d a0 8e 99 81 74 1a 31 f6 48 89 df e8 ba 7f 6d ff 85 c0 74 02 <0f> 0b 48 8b 5b 58 48 83 eb 58 eb da 48 c7 c7 70 8e 99 81 e8 e6
    RIP [<ffffffff81a49c9d>] kmem_cache_init_late+0x40/0x7d
    RSP <ffffffff8195bf78>
    ---[ end trace 2e5587581263f881 ]---

    This patch fixes things for me, but to maintain the rules from
    Christoph's patch, kmalloc_caches[2] should have been created whenever
    kmalloc_caches[7] was done.

    diff --git a/mm/slab_common.c b/mm/slab_common.c
    index d2517b0..ff3218a 100644
    --- a/mm/slab_common.c
    +++ b/mm/slab_common.c
    @@ -446,18 +446,18 @@ void __init create_kmalloc_caches(unsigned long flags)
    if (!kmalloc_caches[i]) {
    kmalloc_caches[i] = create_kmalloc_cache(NULL,
    1 << i, flags);
    + }

    - /*
    - * Caches that are not of the two-to-the-power-of size.
    - * These have to be created immediately after the
    - * earlier power of two caches
    - */
    - if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
    - kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);
    + /*
    + * Caches that are not of the two-to-the-power-of size.
    + * These have to be created immediately after the
    + * earlier power of two caches
    + */
    + if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
    + kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);

    - if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
    - kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
    - }
    + if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
    + kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
    }

    /* Kmalloc array is now usable */

    \
     
     \ /
      Last update: 2013-05-08 20:21    [W:0.030 / U:30.416 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site