On 4/11/22 07:00, Zhangfei Gao wrote: > with this patchset, each time after sbin/nginx, ioasid is freed > immediately. lynx test will alloc the same ioasid=1.
That doesn't seem right. Isn't 'sbin/nginx' still running when lynx runs? How can they get the same ioasid? This sounds like a refcounting problem, like that the ioasid wasn't properly refcounted as nginx forked into the background. > To verify, hack comment mm_pasid_drop in __mmput will make the issue > disappear. > > log: after sbin/nginx. > [ 96.526730] Call trace: > [ 96.526732] dump_backtrace+0xe4/0xf0 > [ 96.526741] show_stack+0x20/0x70 > [ 96.526744] dump_stack_lvl+0x8c/0xb8 > [ 96.526751] dump_stack+0x18/0x34 > [ 96.526754] ioasid_free+0xdc/0xfc > [ 96.526757] mmput+0x138/0x160 > [ 96.526760] do_exit+0x284/0x9d0 > [ 96.526765] do_group_exit+0x3c/0xa8 > [ 96.526767] __wake_up_parent+0x0/0x38 > [ 96.526770] invoke_syscall+0x4c/0x110 > [ 96.526775] el0_svc_common.constprop.0+0x68/0x128 > [ 96.526778] do_el0_svc+0x2c/0x90 > [ 96.526781] el0_svc+0x30/0x98 > [ 96.526783] el0t_64_sync_handler+0xb0/0xb8 > [ 96.526785] el0t_64_sync+0x18c/0x190 Is there nothing before this call trace? Usually there will be at least some warning text. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
