1. 23 10月, 2021 1 次提交
    • J
      sched: make task_struct->plug always defined · 599593a8
      Jens Axboe 提交于
      If CONFIG_BLOCK isn't set, then it's an empty struct anyway. Just make
      it generally available, so we don't break the compile:
      
      kernel/sched/core.c: In function ‘sched_submit_work’:
      kernel/sched/core.c:6346:35: error: ‘struct task_struct’ has no member named ‘plug’
       6346 |                 blk_flush_plug(tsk->plug, true);
            |                                   ^~
      kernel/sched/core.c: In function ‘io_schedule_prepare’:
      kernel/sched/core.c:8357:20: error: ‘struct task_struct’ has no member named ‘plug’
       8357 |         if (current->plug)
            |                    ^~
      kernel/sched/core.c:8358:39: error: ‘struct task_struct’ has no member named ‘plug’
       8358 |                 blk_flush_plug(current->plug, true);
            |                                       ^~
      Reported-by: NNathan Chancellor <nathan@kernel.org>
      Fixes: 008f75a2 ("block: cleanup the flush plug helpers")
      Signed-off-by: NJens Axboe <axboe@kernel.dk>
      599593a8
  2. 22 10月, 2021 10 次提交
  3. 21 10月, 2021 7 次提交
  4. 20 10月, 2021 19 次提交
  5. 19 10月, 2021 3 次提交
    • J
      block: attempt direct issue of plug list · dc5fc361
      Jens Axboe 提交于
      If we have just one queue type in the plug list, then we can extend our
      direct issue to cover a full plug list as well. This allows sending a
      batch of requests for direct issue, which is more efficient than doing
      one-at-a-time kind of issue.
      Reviewed-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NJens Axboe <axboe@kernel.dk>
      dc5fc361
    • J
      block: change plugging to use a singly linked list · bc490f81
      Jens Axboe 提交于
      Use a singly linked list for the blk_plug. This saves 8 bytes in the
      blk_plug struct, and makes for faster list manipulations than doubly
      linked lists. As we don't use the doubly linked lists for anything,
      singly linked is just fine.
      
      This yields a bump in default (merging enabled) performance from 7.0
      to 7.1M IOPS, and ~7.5M IOPS with merging disabled.
      Reviewed-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NJens Axboe <axboe@kernel.dk>
      bc490f81
    • A
      blk-wbt: prevent NULL pointer dereference in wb_timer_fn · 480d42dc
      Andrea Righi 提交于
      The timer callback used to evaluate if the latency is exceeded can be
      executed after the corresponding disk has been released, causing the
      following NULL pointer dereference:
      
      [ 119.987108] BUG: kernel NULL pointer dereference, address: 0000000000000098
      [ 119.987617] #PF: supervisor read access in kernel mode
      [ 119.987971] #PF: error_code(0x0000) - not-present page
      [ 119.988325] PGD 7c4a4067 P4D 7c4a4067 PUD 7bf63067 PMD 0
      [ 119.988697] Oops: 0000 [#1] SMP NOPTI
      [ 119.988959] CPU: 1 PID: 9353 Comm: cloud-init Not tainted 5.15-rc5+arighi #rc5+arighi
      [ 119.989520] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
      [ 119.990055] RIP: 0010:wb_timer_fn+0x44/0x3c0
      [ 119.990376] Code: 41 8b 9c 24 98 00 00 00 41 8b 94 24 b8 00 00 00 41 8b 84 24 d8 00 00 00 4d 8b 74 24 28 01 d3 01 c3 49 8b 44 24 60 48 8b 40 78 <4c> 8b b8 98 00 00 00 4d 85 f6 0f 84 c4 00 00 00 49 83 7c 24 30 00
      [ 119.991578] RSP: 0000:ffffb5f580957da8 EFLAGS: 00010246
      [ 119.991937] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
      [ 119.992412] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88f476d7f780
      [ 119.992895] RBP: ffffb5f580957dd0 R08: 0000000000000000 R09: 0000000000000000
      [ 119.993371] R10: 0000000000000004 R11: 0000000000000002 R12: ffff88f476c84500
      [ 119.993847] R13: ffff88f4434390c0 R14: 0000000000000000 R15: ffff88f4bdc98c00
      [ 119.994323] FS: 00007fb90bcd9c00(0000) GS:ffff88f4bdc80000(0000) knlGS:0000000000000000
      [ 119.994952] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [ 119.995380] CR2: 0000000000000098 CR3: 000000007c0d6000 CR4: 00000000000006e0
      [ 119.995906] Call Trace:
      [ 119.996130] ? blk_stat_free_callback_rcu+0x30/0x30
      [ 119.996505] blk_stat_timer_fn+0x138/0x140
      [ 119.996830] call_timer_fn+0x2b/0x100
      [ 119.997136] __run_timers.part.0+0x1d1/0x240
      [ 119.997470] ? kvm_clock_get_cycles+0x11/0x20
      [ 119.997826] ? ktime_get+0x3e/0xa0
      [ 119.998110] ? native_apic_msr_write+0x2c/0x30
      [ 119.998456] ? lapic_next_event+0x20/0x30
      [ 119.998779] ? clockevents_program_event+0x94/0xf0
      [ 119.999150] run_timer_softirq+0x2a/0x50
      [ 119.999465] __do_softirq+0xcb/0x26f
      [ 119.999764] irq_exit_rcu+0x8c/0xb0
      [ 120.000057] sysvec_apic_timer_interrupt+0x43/0x90
      [ 120.000429] ? asm_sysvec_apic_timer_interrupt+0xa/0x20
      [ 120.000836] asm_sysvec_apic_timer_interrupt+0x12/0x20
      
      In this case simply return from the timer callback (no action
      required) to prevent the NULL pointer dereference.
      
      BugLink: https://bugs.launchpad.net/bugs/1947557
      Link: https://lore.kernel.org/linux-mm/YWRNVTk9N8K0RMst@arighi-desktop/
      Fixes: 34dbad5d ("blk-stat: convert to callback-based statistics reporting")
      Signed-off-by: NAndrea Righi <andrea.righi@canonical.com>
      Link: https://lore.kernel.org/r/YW6N2qXpBU3oc50q@arighi-desktopSigned-off-by: NJens Axboe <axboe@kernel.dk>
      480d42dc