On Wed, Jun 09, 2021 at 01:38:29PM +0200, Vlastimil Babka wrote: > Changes since RFC v1 [1]: > * Addressed feedback from Christoph and Mel, added their acks. > * Finished RT conversion, including adopting 2 patches from the RT tree. > * The optional local_lock conversion has to sacrifice lockless fathpaths on RT > * Added some more cleanup patches to the front. > > This series was initially inspired by Mel's pcplist local_lock rewrite, and > also by interest to better understand SLUB's locking and the new locking > primitives and their RT variants and implications. It should make SLUB more > preemption-friendly and fully RT compatible, hopefully without noticeable > regressions on !RT kernels, as the fast paths are not affected there. > > Series is based on 5.13-rc5 and also available as a git branch: > https://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux.git/log/?h=slub-local-lock-v2r1 > This failed to boot for me inside KVM. [ 0.273576] SRBDS: Unknown: Dependent on hypervisor status [ 0.273576] MDS: Mitigation: Clear CPU buffers [ 0.273576] Freeing SMP alternatives memory: 36K [ 0.273576] bad: scheduling from the idle thread! [ 0.273576] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc5-unspecified+ #1 [ 0.273576] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 0.273576] Call Trace: [ 0.273576] dump_stack+0x76/0x94 [ 0.273576] dequeue_task_idle+0x28/0x40 [ 0.273576] __do_set_cpus_allowed+0xe0/0x1a0 [ 0.273576] __schedule+0x7f7/0x8f0 [ 0.273576] __cond_resched+0x22/0x40 [ 0.273576] alloc_vmap_area+0x72/0x8b0 [ 0.273576] ? kmem_cache_alloc_node_trace+0x189/0x300 [ 0.273576] ? __get_vm_area_node+0x76/0x150 [ 0.273576] __get_vm_area_node+0xab/0x150 [ 0.273576] __vmalloc_node_range+0x6d/0x2c0 [ 0.273576] ? kernel_clone+0x9b/0x3e0 [ 0.273576] ? kmem_cache_alloc_node+0x18d/0x2f0 [ 0.273576] ? copy_process+0x218/0x1c40 [ 0.273576] copy_process+0x2c1/0x1c40 [ 0.273576] ? kernel_clone+0x9b/0x3e0 [ 0.273576] ? enqueue_task_fair+0xa1/0x590 [ 0.273576] kernel_clone+0x9b/0x3e0 [ 0.273576] ? acpi_hw_register_read+0x146/0x166 [ 0.273576] kernel_thread+0x55/0x70 [ 0.273576] ? kthread_is_per_cpu+0x30/0x30 [ 0.273576] rest_init+0x75/0xc0 [ 0.273576] start_kernel+0x7fb/0x822 [ 0.273576] secondary_startup_64_no_verify+0xc2/0xcb [ 0.273576] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 0.273576] #PF: supervisor instruction fetch in kernel mode [ 0.273576] #PF: error_code(0x0010) - not-present page [ 0.273576] PGD 0 P4D 0 [ 0.273576] Oops: 0010 [#1] SMP PTI [ 0.273576] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc5-unspecified+ #1 [ 0.273576] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 0.273576] RIP: 0010:0x0 [ 0.273576] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [ 0.273576] RSP: 0000:ffffffffbb803bb0 EFLAGS: 00010002 [ 0.273576] RAX: 0000000000000000 RBX: ffff9fa64ea2ecc0 RCX: ffffffffb9e00101 [ 0.273576] RDX: 000000000000000a RSI: ffffffffbb81a940 RDI: ffff9fa64ea2ecc0 [ 0.273576] RBP: ffffffffbb803c08 R08: 0000000000000000 R09: ffffffffbbaa699c [ 0.273576] R10: 0000000000000000 R11: ffffffffbb803888 R12: ffffffffbb81a940 [ 0.273576] R13: ffff9f9a80245f40 R14: ffffffffbb1f0060 R15: 0000000000003fff [ 0.273576] FS: 0000000000000000(0000) GS:ffff9fa64ea00000(0000) knlGS:0000000000000000 [ 0.273576] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.273576] CR2: ffffffffffffffd6 CR3: 0000000a60e10001 CR4: 0000000000170ef0 [ 0.273576] Call Trace: [ 0.273576] __schedule+0x7f7/0x8f0 [ 0.273576] __cond_resched+0x22/0x40 [ 0.273576] alloc_vmap_area+0x72/0x8b0 [ 0.273576] ? kmem_cache_alloc_node_trace+0x189/0x300 [ 0.273576] ? __get_vm_area_node+0x76/0x150 [ 0.273576] __get_vm_area_node+0xab/0x150 [ 0.273576] __vmalloc_node_range+0x6d/0x2c0 [ 0.273576] ? kernel_clone+0x9b/0x3e0 [ 0.273576] ? kmem_cache_alloc_node+0x18d/0x2f0 [ 0.273576] ? copy_process+0x218/0x1c40 [ 0.273576] copy_process+0x2c1/0x1c40 [ 0.273576] ? kernel_clone+0x9b/0x3e0 [ 0.273576] ? enqueue_task_fair+0xa1/0x590 [ 0.273576] kernel_clone+0x9b/0x3e0 [ 0.273576] ? acpi_hw_register_read+0x146/0x166 [ 0.273576] kernel_thread+0x55/0x70 [ 0.273576] ? kthread_is_per_cpu+0x30/0x30 [ 0.273576] rest_init+0x75/0xc0 [ 0.273576] start_kernel+0x7fb/0x822 [ 0.273576] secondary_startup_64_no_verify+0xc2/0xcb [ 0.273576] Modules linked in: [ 0.273576] CR2: 0000000000000000 [ 0.273576] ---[ end trace 7199d6fbb50b4cf7 ]--- [ 0.273576] RIP: 0010:0x0 [ 0.273576] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [ 0.273576] RSP: 0000:ffffffffbb803bb0 EFLAGS: 00010002 [ 0.273576] RAX: 0000000000000000 RBX: ffff9fa64ea2ecc0 RCX: ffffffffb9e00101 [ 0.273576] RDX: 000000000000000a RSI: ffffffffbb81a940 RDI: ffff9fa64ea2ecc0 [ 0.273576] RBP: ffffffffbb803c08 R08: 0000000000000000 R09: ffffffffbbaa699c [ 0.273576] R10: 0000000000000000 R11: ffffffffbb803888 R12: ffffffffbb81a940 [ 0.273576] R13: ffff9f9a80245f40 R14: ffffffffbb1f0060 R15: 0000000000003fff [ 0.273576] FS: 0000000000000000(0000) GS:ffff9fa64ea00000(0000) knlGS:0000000000000000 [ 0.273576] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.273576] CR2: ffffffffffffffd6 CR3: 0000000a60e10001 CR4: 0000000000170ef0 [ 0.273576] Kernel panic - not syncing: Attempted to kill the idle task! [ 0.273576] Rebooting in 90 seconds..
