From ef0f7ae934b04a4f90e051d701ba539dd04e7d5b Mon Sep 17 00:00:00 2001 From: Hans Petter Selasky Date: Fri, 21 May 2021 10:27:20 +0200 Subject: [PATCH] The old thread priority must be stored as part of the EPOCH(9) tracker. Else recursive use of EPOCH(9) may cause the wrong priority to be restored. Bump the __FreeBSD_version due to changing the thread and epoch tracker structure. Differential Revision: https://reviews.freebsd.org/D30375 Reviewed by: markj@ MFC after: 1 week Sponsored by: Mellanox Technologies // NVIDIA Networking --- sys/kern/subr_epoch.c | 6 +++--- sys/sys/epoch.h | 1 + sys/sys/param.h | 2 +- sys/sys/proc.h | 1 - 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/sys/kern/subr_epoch.c b/sys/kern/subr_epoch.c index 798dbdc4360e..651fd8b419f0 100644 --- a/sys/kern/subr_epoch.c +++ b/sys/kern/subr_epoch.c @@ -457,7 +457,7 @@ _epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE) THREAD_NO_SLEEPING(); critical_enter(); sched_pin(); - td->td_pre_epoch_prio = td->td_priority; + et->et_old_priority = td->td_priority; er = epoch_currecord(epoch); /* Record-level tracking is reserved for non-preemptible epochs. */ MPASS(er->er_td == NULL); @@ -510,8 +510,8 @@ _epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE) ck_epoch_end(&er->er_record, &et->et_section); TAILQ_REMOVE(&er->er_tdlist, et, et_link); er->er_gen++; - if (__predict_false(td->td_pre_epoch_prio != td->td_priority)) - epoch_adjust_prio(td, td->td_pre_epoch_prio); + if (__predict_false(et->et_old_priority != td->td_priority)) + epoch_adjust_prio(td, et->et_old_priority); critical_exit(); #ifdef EPOCH_TRACE epoch_trace_exit(td, epoch, et, file, line); diff --git a/sys/sys/epoch.h b/sys/sys/epoch.h index 25d2bb3dc6e3..85c791d3df6c 100644 --- a/sys/sys/epoch.h +++ b/sys/sys/epoch.h @@ -55,6 +55,7 @@ struct epoch_tracker { TAILQ_ENTRY(epoch_tracker) et_link; struct thread *et_td; ck_epoch_section_t et_section; + uint8_t et_old_priority; #ifdef EPOCH_TRACE struct epoch *et_epoch; SLIST_ENTRY(epoch_tracker) et_tlink; diff --git a/sys/sys/param.h b/sys/sys/param.h index 68808f3e2185..81971777e87b 100644 --- a/sys/sys/param.h +++ b/sys/sys/param.h @@ -76,7 +76,7 @@ * cannot include sys/param.h and should only be updated here. */ #undef __FreeBSD_version -#define __FreeBSD_version 1400013 +#define __FreeBSD_version 1400014 /* * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD, diff --git a/sys/sys/proc.h b/sys/sys/proc.h index 926f0de14b84..8098bb9468ec 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -325,7 +325,6 @@ struct thread { u_char td_pri_class; /* (t) Scheduling class. */ u_char td_user_pri; /* (t) User pri from estcpu and nice. */ u_char td_base_user_pri; /* (t) Base user pri */ - u_char td_pre_epoch_prio; /* (k) User pri on entry to epoch */ uintptr_t td_rb_list; /* (k) Robust list head. */ uintptr_t td_rbp_list; /* (k) Robust priv list head. */ uintptr_t td_rb_inact; /* (k) Current in-action mutex loc. */