AliyunLinux2 创建快照/镜像 后产生无用的 aliyun-base.repo 引起报错 #4
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casparant
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Jan 16, 2020
commit d4ef647 upstream. In io_sqe_buffer_register() we allocate a number of arrays based on the iov_len from the user-provided iov. While we limit iov_len to SZ_1G, we can still attempt to allocate arrays exceeding MAX_ORDER. On a 64-bit system with 4KiB pages, for an iov where iov_base = 0x10 and iov_len = SZ_1G, we'll calculate that nr_pages = 262145. When we try to allocate a corresponding array of (16-byte) bio_vecs, requiring 4194320 bytes, which is greater than 4MiB. This results in SLUB warning that we're trying to allocate greater than MAX_ORDER, and failing the allocation. Avoid this by using kvmalloc() for allocations dependent on the user-provided iov_len. At the same time, fix a leak of imu->bvec when registration fails. Full splat from before this patch: WARNING: CPU: 1 PID: 2314 at mm/page_alloc.c:4595 __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2314 Comm: syz-executor326 Not tainted 5.1.0-rc7-dirty #4 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x190 lib/dump_stack.c:113 panic+0x384/0x68c kernel/panic.c:214 __warn+0x2bc/0x2c0 kernel/panic.c:571 report_bug+0x228/0x2d8 lib/bug.c:186 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline] brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831 el1_dbg+0x18/0x8c __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 alloc_pages_current+0x164/0x278 mm/mempolicy.c:2132 alloc_pages include/linux/gfp.h:509 [inline] kmalloc_order+0x20/0x50 mm/slab_common.c:1231 kmalloc_order_trace+0x30/0x2b0 mm/slab_common.c:1243 kmalloc_large include/linux/slab.h:480 [inline] __kmalloc+0x3dc/0x4f0 mm/slub.c:3791 kmalloc_array include/linux/slab.h:670 [inline] io_sqe_buffer_register fs/io_uring.c:2472 [inline] __io_uring_register fs/io_uring.c:2962 [inline] __do_sys_io_uring_register fs/io_uring.c:3008 [inline] __se_sys_io_uring_register fs/io_uring.c:2990 [inline] __arm64_sys_io_uring_register+0x9e0/0x1bc8 fs/io_uring.c:2990 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948 SMP: stopping secondary CPUs Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled CPU features: 0x002,23000438 Memory Limit: none Rebooting in 1 seconds.. Fixes: edafcce ("io_uring: add support for pre-mapped user IO buffers") Signed-off-by: Mark Rutland <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Jens Axboe <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Joseph Qi <[email protected]> Reviewed-by: Jeffle Xu <[email protected]> Acked-by: Caspar Zhang <[email protected]>
casparant
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Jan 16, 2020
commit d4ef647 upstream. In io_sqe_buffer_register() we allocate a number of arrays based on the iov_len from the user-provided iov. While we limit iov_len to SZ_1G, we can still attempt to allocate arrays exceeding MAX_ORDER. On a 64-bit system with 4KiB pages, for an iov where iov_base = 0x10 and iov_len = SZ_1G, we'll calculate that nr_pages = 262145. When we try to allocate a corresponding array of (16-byte) bio_vecs, requiring 4194320 bytes, which is greater than 4MiB. This results in SLUB warning that we're trying to allocate greater than MAX_ORDER, and failing the allocation. Avoid this by using kvmalloc() for allocations dependent on the user-provided iov_len. At the same time, fix a leak of imu->bvec when registration fails. Full splat from before this patch: WARNING: CPU: 1 PID: 2314 at mm/page_alloc.c:4595 __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2314 Comm: syz-executor326 Not tainted 5.1.0-rc7-dirty #4 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x190 lib/dump_stack.c:113 panic+0x384/0x68c kernel/panic.c:214 __warn+0x2bc/0x2c0 kernel/panic.c:571 report_bug+0x228/0x2d8 lib/bug.c:186 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline] brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831 el1_dbg+0x18/0x8c __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 alloc_pages_current+0x164/0x278 mm/mempolicy.c:2132 alloc_pages include/linux/gfp.h:509 [inline] kmalloc_order+0x20/0x50 mm/slab_common.c:1231 kmalloc_order_trace+0x30/0x2b0 mm/slab_common.c:1243 kmalloc_large include/linux/slab.h:480 [inline] __kmalloc+0x3dc/0x4f0 mm/slub.c:3791 kmalloc_array include/linux/slab.h:670 [inline] io_sqe_buffer_register fs/io_uring.c:2472 [inline] __io_uring_register fs/io_uring.c:2962 [inline] __do_sys_io_uring_register fs/io_uring.c:3008 [inline] __se_sys_io_uring_register fs/io_uring.c:2990 [inline] __arm64_sys_io_uring_register+0x9e0/0x1bc8 fs/io_uring.c:2990 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948 SMP: stopping secondary CPUs Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled CPU features: 0x002,23000438 Memory Limit: none Rebooting in 1 seconds.. Fixes: edafcce ("io_uring: add support for pre-mapped user IO buffers") Signed-off-by: Mark Rutland <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Jens Axboe <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Joseph Qi <[email protected]> Reviewed-by: Jeffle Xu <[email protected]> Acked-by: Caspar Zhang <[email protected]>
casparant
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Jan 17, 2020
commit d4ef647 upstream. In io_sqe_buffer_register() we allocate a number of arrays based on the iov_len from the user-provided iov. While we limit iov_len to SZ_1G, we can still attempt to allocate arrays exceeding MAX_ORDER. On a 64-bit system with 4KiB pages, for an iov where iov_base = 0x10 and iov_len = SZ_1G, we'll calculate that nr_pages = 262145. When we try to allocate a corresponding array of (16-byte) bio_vecs, requiring 4194320 bytes, which is greater than 4MiB. This results in SLUB warning that we're trying to allocate greater than MAX_ORDER, and failing the allocation. Avoid this by using kvmalloc() for allocations dependent on the user-provided iov_len. At the same time, fix a leak of imu->bvec when registration fails. Full splat from before this patch: WARNING: CPU: 1 PID: 2314 at mm/page_alloc.c:4595 __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2314 Comm: syz-executor326 Not tainted 5.1.0-rc7-dirty #4 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2f0 include/linux/compiler.h:193 show_stack+0x20/0x30 arch/arm64/kernel/traps.c:158 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x190 lib/dump_stack.c:113 panic+0x384/0x68c kernel/panic.c:214 __warn+0x2bc/0x2c0 kernel/panic.c:571 report_bug+0x228/0x2d8 lib/bug.c:186 bug_handler+0xa0/0x1a0 arch/arm64/kernel/traps.c:956 call_break_hook arch/arm64/kernel/debug-monitors.c:301 [inline] brk_handler+0x1d4/0x388 arch/arm64/kernel/debug-monitors.c:316 do_debug_exception+0x1a0/0x468 arch/arm64/mm/fault.c:831 el1_dbg+0x18/0x8c __alloc_pages_nodemask+0x7ac/0x2938 mm/page_alloc.c:4595 alloc_pages_current+0x164/0x278 mm/mempolicy.c:2132 alloc_pages include/linux/gfp.h:509 [inline] kmalloc_order+0x20/0x50 mm/slab_common.c:1231 kmalloc_order_trace+0x30/0x2b0 mm/slab_common.c:1243 kmalloc_large include/linux/slab.h:480 [inline] __kmalloc+0x3dc/0x4f0 mm/slub.c:3791 kmalloc_array include/linux/slab.h:670 [inline] io_sqe_buffer_register fs/io_uring.c:2472 [inline] __io_uring_register fs/io_uring.c:2962 [inline] __do_sys_io_uring_register fs/io_uring.c:3008 [inline] __se_sys_io_uring_register fs/io_uring.c:2990 [inline] __arm64_sys_io_uring_register+0x9e0/0x1bc8 fs/io_uring.c:2990 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common.constprop.0+0x148/0x2e0 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0xdc/0x100 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:948 SMP: stopping secondary CPUs Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled CPU features: 0x002,23000438 Memory Limit: none Rebooting in 1 seconds.. Fixes: edafcce ("io_uring: add support for pre-mapped user IO buffers") Signed-off-by: Mark Rutland <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Jens Axboe <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Joseph Qi <[email protected]> Reviewed-by: Jeffle Xu <[email protected]> Acked-by: Caspar Zhang <[email protected]>
casparant
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Jun 10, 2020
to #28170604 commit 8e2e1fa upstream syzbot reports this crash: BUG: unable to handle page fault for address: ffffffffffffffe8 PGD f96e17067 P4D f96e17067 PUD f96e19067 PMD 0 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI CPU: 55 PID: 211750 Comm: trinity-c127 Tainted: G B L 5.7.0-rc1-next-20200413 #4 Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 04/12/2017 RIP: 0010:__wake_up_common+0x98/0x290 el/sched/wait.c:87 Code: 40 4d 8d 78 e8 49 8d 7f 18 49 39 fd 0f 84 80 00 00 00 e8 6b bd 2b 00 49 8b 5f 18 45 31 e4 48 83 eb 18 4c 89 ff e8 08 bc 2b 00 <45> 8b 37 41 f6 c6 04 75 71 49 8d 7f 10 e8 46 bd 2b 00 49 8b 47 10 RSP: 0018:ffffc9000adbfaf0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffffffffffffe8 RCX: ffffffffaa9636b8 RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffffffffffffffe8 RBP: ffffc9000adbfb40 R08: fffffbfff582c5fd R09: fffffbfff582c5fd R10: ffffffffac162fe3 R11: fffffbfff582c5fc R12: 0000000000000000 R13: ffff888ef82b0960 R14: ffffc9000adbfb80 R15: ffffffffffffffe8 FS: 00007fdcba4c4740(0000) GS:ffff889033780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffe8 CR3: 0000000f776a0004 CR4: 00000000001606e0 Call Trace: __wake_up_common_lock+0xea/0x150 ommon_lock at kernel/sched/wait.c:124 ? __wake_up_common+0x290/0x290 ? lockdep_hardirqs_on+0x16/0x2c0 __wake_up+0x13/0x20 io_cqring_ev_posted+0x75/0xe0 v_posted at fs/io_uring.c:1160 io_ring_ctx_wait_and_kill+0x1c0/0x2f0 l at fs/io_uring.c:7305 io_uring_create+0xa8d/0x13b0 ? io_req_defer_prep+0x990/0x990 ? __kasan_check_write+0x14/0x20 io_uring_setup+0xb8/0x130 ? io_uring_create+0x13b0/0x13b0 ? check_flags.part.28+0x220/0x220 ? lockdep_hardirqs_on+0x16/0x2c0 __x64_sys_io_uring_setup+0x31/0x40 do_syscall_64+0xcc/0xaf0 ? syscall_return_slowpath+0x580/0x580 ? lockdep_hardirqs_off+0x1f/0x140 ? entry_SYSCALL_64_after_hwframe+0x3e/0xb3 ? trace_hardirqs_off_caller+0x3a/0x150 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7fdcb9dd76ed Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 6b 57 2c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe7fd4e4f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00000000000001a9 RCX: 00007fdcb9dd76ed RDX: fffffffffffffffc RSI: 0000000000000000 RDI: 0000000000005d54 RBP: 00000000000001a9 R08: 0000000e31d3caa7 R09: 0082400004004000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000002 R13: 00007fdcb842e058 R14: 00007fdcba4c46c0 R15: 00007fdcb842e000 Modules linked in: bridge stp llc nfnetlink cn brd vfat fat ext4 crc16 mbcache jbd2 loop kvm_intel kvm irqbypass intel_cstate intel_uncore dax_pmem intel_rapl_perf dax_pmem_core ip_tables x_tables xfs sd_mod tg3 firmware_class libphy hpsa scsi_transport_sas dm_mirror dm_region_hash dm_log dm_mod [last unloaded: binfmt_misc] CR2: ffffffffffffffe8 ---[ end trace f9502383d57e0e22 ]--- RIP: 0010:__wake_up_common+0x98/0x290 Code: 40 4d 8d 78 e8 49 8d 7f 18 49 39 fd 0f 84 80 00 00 00 e8 6b bd 2b 00 49 8b 5f 18 45 31 e4 48 83 eb 18 4c 89 ff e8 08 bc 2b 00 <45> 8b 37 41 f6 c6 04 75 71 49 8d 7f 10 e8 46 bd 2b 00 49 8b 47 10 RSP: 0018:ffffc9000adbfaf0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffffffffffffe8 RCX: ffffffffaa9636b8 RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffffffffffffffe8 RBP: ffffc9000adbfb40 R08: fffffbfff582c5fd R09: fffffbfff582c5fd R10: ffffffffac162fe3 R11: fffffbfff582c5fc R12: 0000000000000000 R13: ffff888ef82b0960 R14: ffffc9000adbfb80 R15: ffffffffffffffe8 FS: 00007fdcba4c4740(0000) GS:ffff889033780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffe8 CR3: 0000000f776a0004 CR4: 00000000001606e0 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x29800000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) ---[ end Kernel panic - not syncing: Fatal exception ]— which is due to error injection (or allocation failure) preventing the rings from being setup. On shutdown, we attempt to remove any pending requests, and for poll request, we call io_cqring_ev_posted() when we've killed poll requests. However, since the rings aren't setup, we won't find any poll requests. Make the calling of io_cqring_ev_posted() dependent on actually having completed requests. This fixes this setup corner case, and removes spurious calls if we remove poll requests and don't find any. Reported-by: Qian Cai <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Acked-by: Joseph Qi <[email protected]> Signed-off-by: Xiaoguang Wang <[email protected]> Signed-off-by: Xiaoguang Wang <[email protected]>
casparant
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Sep 1, 2020
task #28557737 [ Upstream commit 6c5d911 ] journal_head::b_transaction and journal_head::b_next_transaction could be accessed concurrently as noticed by KCSAN, LTP: starting fsync04 /dev/zero: Can't open blockdev EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null) ================================================================== BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2] write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70: __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2] __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569 jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2] (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034 kjournald2+0x13b/0x450 [jbd2] kthread+0x1cd/0x1f0 ret_from_fork+0x27/0x50 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68: jbd2_write_access_granted+0x1b2/0x250 [jbd2] jbd2_write_access_granted at fs/jbd2/transaction.c:1155 jbd2_journal_get_write_access+0x2c/0x60 [jbd2] __ext4_journal_get_write_access+0x50/0x90 [ext4] ext4_mb_mark_diskspace_used+0x158/0x620 [ext4] ext4_mb_new_blocks+0x54f/0xca0 [ext4] ext4_ind_map_blocks+0xc79/0x1b40 [ext4] ext4_map_blocks+0x3b4/0x950 [ext4] _ext4_get_block+0xfc/0x270 [ext4] ext4_get_block+0x3b/0x50 [ext4] __block_write_begin_int+0x22e/0xae0 __block_write_begin+0x39/0x50 ext4_write_begin+0x388/0xb50 [ext4] generic_perform_write+0x15d/0x290 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe 5 locks held by fsync04/25724: #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260 #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4] #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2] #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4] #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2] irq event stamp: 1407125 hardirqs last enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790 softirqs last enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 The plain reads are outside of jh->b_state_lock critical section which result in data races. Fix them by adding pairs of READ|WRITE_ONCE(). Reviewed-by: Jan Kara <[email protected]> Signed-off-by: Qian Cai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Theodore Ts'o <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Jeffle Xu <[email protected]> Acked-by: Joseph Qi <[email protected]>
casparant
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Jan 19, 2021
task #31256938 commit 5df7419 upstream The reclaim code that balances between swapping and cache reclaim tries to predict likely reuse based on in-memory reference patterns alone. This works in many cases, but when it fails it cannot detect when the cache is thrashing pathologically, or when we're in the middle of a swap storm. The high seek cost of rotational drives under which the algorithm evolved also meant that mistakes could quickly result in lockups from too aggressive swapping (which is predominantly random IO). As a result, the balancing code has been tuned over time to a point where it mostly goes for page cache and defers swapping until the VM is under significant memory pressure. The resulting strategy doesn't make optimal caching decisions - where optimal is the least amount of IO required to execute the workload. The proliferation of fast random IO devices such as SSDs, in-memory compression such as zswap, and persistent memory technologies on the horizon, has made this undesirable behavior very noticable: Even in the presence of large amounts of cold anonymous memory and a capable swap device, the VM refuses to even seriously scan these pages, and can leave the page cache thrashing needlessly. This series sets out to address this. Since commit ("a528910e12ec mm: thrash detection-based file cache sizing") we have exact tracking of refault IO - the ultimate cost of reclaiming the wrong pages. This allows us to use an IO cost based balancing model that is more aggressive about scanning anonymous memory when the cache is thrashing, while being able to avoid unnecessary swap storms. These patches base the LRU balance on the rate of refaults on each list, times the relative IO cost between swap device and filesystem (swappiness), in order to optimize reclaim for least IO cost incurred. History I floated these changes in 2016. At the time they were incomplete and full of workarounds due to a lack of infrastructure in the reclaim code: We didn't have PageWorkingset, we didn't have hierarchical cgroup statistics, and problems with the cgroup swap controller. As swapping wasn't too high a priority then, the patches stalled out. With all dependencies in place now, here we are again with much cleaner, feature-complete patches. I kept the acks for patches that stayed materially the same :-) Below is a series of test results that demonstrate certain problematic behavior of the current code, as well as showcase the new code's more predictable and appropriate balancing decisions. Test #1: No convergence This test shows an edge case where the VM currently doesn't converge at all on a new file workingset with a stale anon/tmpfs set. The test sets up a cold anon set the size of 3/4 RAM, then tries to establish a new file set half the size of RAM (flat access pattern). The vanilla kernel refuses to even scan anon pages and never converges. The file set is perpetually served from the filesystem. The first test kernel is with the series up to the workingset patch applied. This allows thrashing page cache to challenge the anonymous workingset. The VM then scans the lists based on the current scanned/rotated balancing algorithm. It converges on a stable state where all cold anon pages are pushed out and the fileset is served entirely from cache: noconverge/5.7-rc5-mm noconverge/5.7-rc5-mm-workingset Scanned 417719308.00 ( +0.00%) 64091155.00 ( -84.66%) Reclaimed 417711094.00 ( +0.00%) 61640308.00 ( -85.24%) Reclaim efficiency % 100.00 ( +0.00%) 96.18 ( -3.78%) Scanned file 417719308.00 ( +0.00%) 59211118.00 ( -85.83%) Scanned anon 0.00 ( +0.00%) 4880037.00 ( ) Swapouts 0.00 ( +0.00%) 2439957.00 ( ) Swapins 0.00 ( +0.00%) 257.00 ( ) Refaults 415246605.00 ( +0.00%) 59183722.00 ( -85.75%) Restore refaults 0.00 ( +0.00%) 54988252.00 ( ) The second test kernel is with the full patch series applied, which replaces the scanned/rotated ratios with refault/swapin rate-based balancing. It evicts the cold anon pages more aggressively in the presence of a thrashing cache and the absence of swapins, and so converges with about 60% of the IO and reclaim activity: noconverge/5.7-rc5-mm-workingset noconverge/5.7-rc5-mm-lrubalance Scanned 64091155.00 ( +0.00%) 37579741.00 ( -41.37%) Reclaimed 61640308.00 ( +0.00%) 35129293.00 ( -43.01%) Reclaim efficiency % 96.18 ( +0.00%) 93.48 ( -2.78%) Scanned file 59211118.00 ( +0.00%) 32708385.00 ( -44.76%) Scanned anon 4880037.00 ( +0.00%) 4871356.00 ( -0.18%) Swapouts 2439957.00 ( +0.00%) 2435565.00 ( -0.18%) Swapins 257.00 ( +0.00%) 262.00 ( +1.94%) Refaults 59183722.00 ( +0.00%) 32675667.00 ( -44.79%) Restore refaults 54988252.00 ( +0.00%) 28480430.00 ( -48.21%) We're triggering this case in host sideloading scenarios: When a host's primary workload is not saturating the machine (primary load is usually driven by user activity), we can optimistically sideload a batch job; if user activity picks up and the primary workload needs the whole host during this time, we freeze the sideload and rely on it getting pushed to swap. Frequently that swapping doesn't happen and the completely inactive sideload simply stays resident while the expanding primary worklad is struggling to gain ground. Test #2: Kernel build This test is a a kernel build that is slightly memory-restricted (make -j4 inside a 400M cgroup). Despite the very aggressive swapping of cold anon pages in test #1, this test shows that the new kernel carefully balances swap against cache refaults when both the file and the cache set are pressured. It shows the patched kernel to be slightly better at finding the coldest memory from the combined anon and file set to evict under pressure. The result is lower aggregate reclaim and paging activity: z 5.7-rc5-mm 5.7-rc5-mm-lrubalance Real time 210.60 ( +0.00%) 210.97 ( +0.18%) User time 745.42 ( +0.00%) 746.48 ( +0.14%) System time 69.78 ( +0.00%) 69.79 ( +0.02%) Scanned file 354682.00 ( +0.00%) 293661.00 ( -17.20%) Scanned anon 465381.00 ( +0.00%) 378144.00 ( -18.75%) Swapouts 185920.00 ( +0.00%) 147801.00 ( -20.50%) Swapins 34583.00 ( +0.00%) 32491.00 ( -6.05%) Refaults 212664.00 ( +0.00%) 172409.00 ( -18.93%) Restore refaults 48861.00 ( +0.00%) 80091.00 ( +63.91%) Total paging IO 433167.00 ( +0.00%) 352701.00 ( -18.58%) Test #3: Overload This next test is not about performance, but rather about the predictability of the algorithm. The current balancing behavior doesn't always lead to comprehensible results, which makes performance analysis and parameter tuning (swappiness e.g.) very difficult. The test shows the balancing behavior under equivalent anon and file input. Anon and file sets are created of equal size (3/4 RAM), have the same access patterns (a hot-cold gradient), and synchronized access rates. Swappiness is raised from the default of 60 to 100 to indicate equal IO cost between swap and cache. With the vanilla balancing code, anon scans make up around 9% of the total pages scanned, or a ~1:10 ratio. This is a surprisingly skewed ratio, and it's an outcome that is hard to explain given the input parameters to the VM. The new balancing model targets a 1:2 balance: All else being equal, reclaiming a file page costs one page IO - the refault; reclaiming an anon page costs two IOs - the swapout and the swapin. In the test we observe a ~1:3 balance. The scanned and paging IO numbers indicate that the anon LRU algorithm we have in place right now does a slightly worse job at picking the coldest pages compared to the file algorithm. There is ongoing work to improve this, like Joonsoo's anon workingset patches; however, it's difficult to compare the two aging strategies when the balancing between them is behaving unintuitively. The slightly less efficient anon reclaim results in a deviation from the optimal 1:2 scan ratio we would like to see here - however, 1:3 is much closer to what we'd want to see in this test than the vanilla kernel's aging of 10+ cache pages for every anonymous one: overload-100/5.7-rc5-mm-workingset overload-100/5.7-rc5-mm-lrubalance-realfile Scanned 533633725.00 ( +0.00%) 595687785.00 ( +11.63%) Reclaimed 494325440.00 ( +0.00%) 518154380.00 ( +4.82%) Reclaim efficiency % 92.63 ( +0.00%) 86.98 ( -6.03%) Scanned file 484532894.00 ( +0.00%) 456937722.00 ( -5.70%) Scanned anon 49100831.00 ( +0.00%) 138750063.00 ( +182.58%) Swapouts 8096423.00 ( +0.00%) 48982142.00 ( +504.98%) Swapins 10027384.00 ( +0.00%) 62325044.00 ( +521.55%) Refaults 479819973.00 ( +0.00%) 451309483.00 ( -5.94%) Restore refaults 426422087.00 ( +0.00%) 399914067.00 ( -6.22%) Total paging IO 497943780.00 ( +0.00%) 562616669.00 ( +12.99%) Test #4: Parallel IO It's important to note that these patches only affect the situation where the kernel has to reclaim workingset memory, which is usually a transitionary period. The vast majority of page reclaim occuring in a system is from trimming the ever-expanding page cache. These patches don't affect cache trimming behavior. We never swap as long as we only have use-once cache moving through the file LRU, we only consider swapping when the cache is actively thrashing. The following test demonstrates this. It has an anon workingset that takes up half of RAM and then writes a file that is twice the size of RAM out to disk. As the cache is funneled through the inactive file list, no anon pages are scanned (aside from apparently some background noise of 10 pages): 5.7-rc5-mm 5.7-rc5-mm-lrubalance Scanned 10714722.00 ( +0.00%) 10723445.00 ( +0.08%) Reclaimed 10703596.00 ( +0.00%) 10712166.00 ( +0.08%) Reclaim efficiency % 99.90 ( +0.00%) 99.89 ( -0.00%) Scanned file 10714722.00 ( +0.00%) 10723435.00 ( +0.08%) Scanned anon 0.00 ( +0.00%) 10.00 ( ) Swapouts 0.00 ( +0.00%) 7.00 ( ) Swapins 0.00 ( +0.00%) 0.00 ( +0.00%) Refaults 92.00 ( +0.00%) 41.00 ( -54.84%) Restore refaults 0.00 ( +0.00%) 0.00 ( +0.00%) Total paging IO 92.00 ( +0.00%) 48.00 ( -47.31%) This patch (of 14): Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless. Always account THP by the number of basepages, and remove the fixup from the splitting path. Signed-off-by: Johannes Weiner <[email protected]> Signed-off-by: Shakeel Butt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Rik van Riel <[email protected]> Reviewed-by: Shakeel Butt <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Minchan Kim <[email protected]> Cc: Joonsoo Kim <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: zhongjiang-ali <[email protected]> Reviewed-by: Xunlei Pang <[email protected]>
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to #30401861 commit c3b7112 upstream Avoid calling cgroup_threadgroup_change_end() without having called cgroup_threadgroup_change_begin() first. During process creation we need to check whether the cgroup we are in allows us to fork. To perform this check the cgroup needs to guard itself against threadgroup changes and takes a lock. Prior to CLONE_PIDFD the cleanup target "bad_fork_free_pid" would also need to call cgroup_threadgroup_change_end() because said lock had already been taken. However, this is not the case anymore with the addition of CLONE_PIDFD. We are now allocating a pidfd before we check whether the cgroup we're in can fork and thus prior to taking the lock. So when copy_process() fails at the right step it would release a lock we haven't taken. This bug is not even very subtle to be honest. It's just not very clear from the naming of cgroup_threadgroup_change_{begin,end}() that a lock is taken. Here's the relevant splat: entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7fec849 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078 RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000 RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ------------[ cut here ]------------ DEBUG_LOCKS_WARN_ON(depth <= 0) WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052 __lock_release kernel/locking/lockdep.c:4052 [inline] WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052 lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7744 Comm: syz-executor007 Not tainted 5.1.0+ #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2cb/0x65c kernel/panic.c:214 __warn.cold+0x20/0x45 kernel/panic.c:566 report_bug+0x263/0x2b0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] fixup_bug arch/x86/kernel/traps.c:174 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:972 RIP: 0010:__lock_release kernel/locking/lockdep.c:4052 [inline] RIP: 0010:lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321 Code: 0f 85 a0 03 00 00 8b 35 77 66 08 08 85 f6 75 23 48 c7 c6 a0 55 6b 87 48 c7 c7 40 25 6b 87 4c 89 85 70 ff ff ff e8 b7 a9 eb ff <0f> 0b 4c 8b 85 70 ff ff ff 4c 89 ea 4c 89 e6 4c 89 c7 e8 52 63 ff RSP: 0018:ffff888094117b48 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 1ffff11012822f6f RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815af236 RDI: ffffed1012822f5b RBP: ffff888094117c00 R08: ffff888092bfc400 R09: fffffbfff113301d R10: fffffbfff113301c R11: ffffffff889980e3 R12: ffffffff8a451df8 R13: ffffffff8142e71f R14: ffffffff8a44cc80 R15: ffff888094117bd8 percpu_up_read.constprop.0+0xcb/0x110 include/linux/percpu-rwsem.h:92 cgroup_threadgroup_change_end include/linux/cgroup-defs.h:712 [inline] copy_process.part.0+0x47ff/0x6710 kernel/fork.c:2222 copy_process kernel/fork.c:1772 [inline] _do_fork+0x25d/0xfd0 kernel/fork.c:2338 __do_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:240 [inline] __se_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:236 [inline] __ia32_compat_sys_x86_clone+0xbc/0x140 arch/x86/ia32/sys_ia32.c:236 do_syscall_32_irqs_on arch/x86/entry/common.c:334 [inline] do_fast_syscall_32+0x281/0xd54 arch/x86/entry/common.c:405 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7fec849 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078 RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000 RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Reported-and-tested-by: [email protected] Fixes: b3e5838 ("clone: add CLONE_PIDFD") Signed-off-by: Christian Brauner <[email protected]> Signed-off-by: Yang, Wei <[email protected]> Reviewed-by: Xunlei Pang <[email protected]>
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OpenAnolis Bug Tracker: 0000566 fix #31401845 commit 58fe03d upstream Disabling a display on MST can potentially happen after the entire MST topology has been removed, which means that we can't communicate with the topology at all in this scenario. Likewise, this also means that we can't properly update payloads on the topology and as such, it's a good idea to ignore payload update failures when disabling displays. Currently, amdgpu makes the mistake of halting the payload update process when any payload update failures occur, resulting in leaving DC's local copies of the payload tables out of date. This ends up causing problems with hotplugging MST topologies, and causes modesets on the second hotplug to fail like so: [drm] Failed to updateMST allocation table forpipe idx:1 ------------[ cut here ]------------ WARNING: CPU: 5 PID: 1511 at drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:2677 update_mst_stream_alloc_table+0x11e/0x130 [amdgpu] Modules linked in: cdc_ether usbnet fuse xt_conntrack nf_conntrack nf_defrag_ipv6 libcrc32c nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 nft_counter nft_compat nf_tables nfnetlink tun bridge stp llc sunrpc vfat fat wmi_bmof uvcvideo snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi videobuf2_vmalloc snd_hda_intel videobuf2_memops videobuf2_v4l2 snd_intel_dspcfg videobuf2_common crct10dif_pclmul snd_hda_codec videodev crc32_pclmul snd_hwdep snd_hda_core ghash_clmulni_intel snd_seq mc joydev pcspkr snd_seq_device snd_pcm sp5100_tco k10temp i2c_piix4 snd_timer thinkpad_acpi ledtrig_audio snd wmi soundcore video i2c_scmi acpi_cpufreq ip_tables amdgpu(O) rtsx_pci_sdmmc amd_iommu_v2 gpu_sched mmc_core i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm crc32c_intel serio_raw hid_multitouch r8152 mii nvme r8169 nvme_core rtsx_pci pinctrl_amd CPU: 5 PID: 1511 Comm: gnome-shell Tainted: G O 5.5.0-rc7Lyude-Test+ #4 Hardware name: LENOVO FA495SIT26/FA495SIT26, BIOS R12ET22W(0.22 ) 01/31/2019 RIP: 0010:update_mst_stream_alloc_table+0x11e/0x130 [amdgpu] Code: 28 00 00 00 75 2b 48 8d 65 e0 5b 41 5c 41 5d 41 5e 5d c3 0f b6 06 49 89 1c 24 41 88 44 24 08 0f b6 46 01 41 88 44 24 09 eb 93 <0f> 0b e9 2f ff ff ff e8 a6 82 a3 c2 66 0f 1f 44 00 00 0f 1f 44 00 RSP: 0018:ffffac428127f5b0 EFLAGS: 00010202 RAX: 0000000000000002 RBX: ffff8d1e166eee80 RCX: 0000000000000000 RDX: ffffac428127f668 RSI: ffff8d1e166eee80 RDI: ffffac428127f610 RBP: ffffac428127f640 R08: ffffffffc03d94a8 R09: 0000000000000000 R10: ffff8d1e24b02000 R11: ffffac428127f5b0 R12: ffff8d1e1b83d000 R13: ffff8d1e1bea0b08 R14: 0000000000000002 R15: 0000000000000002 FS: 00007fab23ffcd80(0000) GS:ffff8d1e28b40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f151f1711e8 CR3: 00000005997c0000 CR4: 00000000003406e0 Call Trace: ? mutex_lock+0xe/0x30 dc_link_allocate_mst_payload+0x9a/0x210 [amdgpu] ? dm_read_reg_func+0x39/0xb0 [amdgpu] ? core_link_enable_stream+0x656/0x730 [amdgpu] core_link_enable_stream+0x656/0x730 [amdgpu] dce110_apply_ctx_to_hw+0x58e/0x5d0 [amdgpu] ? dcn10_verify_allow_pstate_change_high+0x1d/0x280 [amdgpu] ? dcn10_wait_for_mpcc_disconnect+0x3c/0x130 [amdgpu] dc_commit_state+0x292/0x770 [amdgpu] ? add_timer+0x101/0x1f0 ? ttm_bo_put+0x1a1/0x2f0 [ttm] amdgpu_dm_atomic_commit_tail+0xb59/0x1ff0 [amdgpu] ? amdgpu_move_blit.constprop.0+0xb8/0x1f0 [amdgpu] ? amdgpu_bo_move+0x16d/0x2b0 [amdgpu] ? ttm_bo_handle_move_mem+0x118/0x570 [ttm] ? ttm_bo_validate+0x134/0x150 [ttm] ? dm_plane_helper_prepare_fb+0x1b9/0x2a0 [amdgpu] ? _cond_resched+0x15/0x30 ? wait_for_completion_timeout+0x38/0x160 ? _cond_resched+0x15/0x30 ? wait_for_completion_interruptible+0x33/0x190 commit_tail+0x94/0x130 [drm_kms_helper] drm_atomic_helper_commit+0x113/0x140 [drm_kms_helper] drm_atomic_helper_set_config+0x70/0xb0 [drm_kms_helper] drm_mode_setcrtc+0x194/0x6a0 [drm] ? _cond_resched+0x15/0x30 ? mutex_lock+0xe/0x30 ? drm_mode_getcrtc+0x180/0x180 [drm] drm_ioctl_kernel+0xaa/0xf0 [drm] drm_ioctl+0x208/0x390 [drm] ? drm_mode_getcrtc+0x180/0x180 [drm] amdgpu_drm_ioctl+0x49/0x80 [amdgpu] do_vfs_ioctl+0x458/0x6d0 ksys_ioctl+0x5e/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x55/0x1b0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fab2121f87b Code: 0f 1e fa 48 8b 05 0d 96 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d dd 95 2c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd045f9068 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffd045f90a0 RCX: 00007fab2121f87b RDX: 00007ffd045f90a0 RSI: 00000000c06864a2 RDI: 000000000000000b RBP: 00007ffd045f90a0 R08: 0000000000000000 R09: 000055dbd2985d10 R10: 000055dbd2196280 R11: 0000000000000246 R12: 00000000c06864a2 R13: 000000000000000b R14: 0000000000000000 R15: 000055dbd2196280 ---[ end trace 6ea888c24d2059cd ]--- Note as well, I have only been able to reproduce this on setups with 2 MST displays. Changes since v1: * Don't return false when part 1 or part 2 of updating the payloads fails, we don't want to abort at any step of the process even if things fail Reviewed-by: Mikita Lipski <[email protected]> Signed-off-by: Lyude Paul <[email protected]> Acked-by: Harry Wentland <[email protected]> Cc: [email protected] Signed-off-by: Alex Deucher <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Jerry Yao <[email protected]> Acked-by: Baolin Wang <[email protected]> Signed-off-by: Xunlei Pang <[email protected]>
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[问题描述]：
用公共镜像，yum update 了一下系统
制作快照
停机后回滚快照，生成了 aliyun-base 的repo。 （初步怀疑是cloud-init出来的，因为初始的公共镜像只有 AliYun 的 repo）
里面的baseurl是 http://mirrors.cloud.aliyuncs.com/aliyunlinux/15.01/os/$basearch/， 这个地址下只有 15.01 的老的库，没有2版本的库，引用系统变量，yum 就会报错。
有修改 os-release 和 alinux-release 为 CentOS，可能会成为干扰项导致cloud-init出错
[建议方案]：
修复 cloud-init 相关问题
已经同步至聆听平台： https://connect.aliyun.com/suggestion/142611
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