The branch main has been updated by trasz: URL: https://cgit.FreeBSD.org/src/commit/?id=626d6992ca6deff3c4738a01e8c4798989cc9ec7
commit 626d6992ca6deff3c4738a01e8c4798989cc9ec7 Author: Edward Tomasz Napierala <[email protected]> AuthorDate: 2021-12-26 17:22:16 +0000 Commit: Edward Tomasz Napierala <[email protected]> CommitDate: 2021-12-26 17:22:21 +0000 Move fork_rfppwait() check into ast() This will always sleep at least once, so it's a slow path by definition. Reviewed By: kib Sponsored By: EPSRC Differential Revision: https://reviews.freebsd.org/D33387 --- sys/kern/kern_fork.c | 6 ++++++ sys/kern/subr_syscall.c | 3 --- sys/kern/subr_trap.c | 2 ++ 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c index 5b518a0183d8..a6d83fc8049d 100644 --- a/sys/kern/kern_fork.c +++ b/sys/kern/kern_fork.c @@ -484,6 +484,12 @@ do_fork(struct thread *td, struct fork_req *fr, struct proc *p2, struct thread * */ thread_lock(td); sched_fork(td, td2); + /* + * Request AST to check for TDP_RFPPWAIT. Do it here + * to avoid calling thread_lock() again. + */ + if ((fr->fr_flags & RFPPWAIT) != 0) + td->td_flags |= TDF_ASTPENDING; thread_unlock(td); /* diff --git a/sys/kern/subr_syscall.c b/sys/kern/subr_syscall.c index dacd82f4c466..fa5dcb482f2c 100644 --- a/sys/kern/subr_syscall.c +++ b/sys/kern/subr_syscall.c @@ -285,7 +285,4 @@ syscallret(struct thread *td) td->td_dbgflags &= ~(TDB_SCX | TDB_EXEC | TDB_FORK); PROC_UNLOCK(p); } - - if (__predict_false(td->td_pflags & TDP_RFPPWAIT)) - fork_rfppwait(td); } diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c index 2b86fe75776f..ec8f686a497d 100644 --- a/sys/kern/subr_trap.c +++ b/sys/kern/subr_trap.c @@ -259,6 +259,8 @@ ast(struct trapframe *framep) if (PMC_IS_PENDING_CALLCHAIN(td)) PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_USER_CALLCHAIN_SOFT, (void *) framep); #endif + if ((td->td_pflags & TDP_RFPPWAIT) != 0) + fork_rfppwait(td); if (flags & TDF_ALRMPEND) { PROC_LOCK(p); kern_psignal(p, SIGVTALRM);
