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| author | julian <julian@FreeBSD.org> | 2002-02-22 23:58:22 +0000 |
|---|---|---|
| committer | julian <julian@FreeBSD.org> | 2002-02-22 23:58:22 +0000 |
| commit | 53eb1d92192d6566baf1ef330f636ab7b9d70f4f (patch) | |
| tree | 7d75b1e48c3b7ef34eb52967d22fcf93f2addadc /sys/kern/kern_fork.c | |
| parent | 5b69d7da62f2398a3ef361c86be5ab099fd92ad0 (diff) | |
| download | FreeBSD-src-53eb1d92192d6566baf1ef330f636ab7b9d70f4f.zip FreeBSD-src-53eb1d92192d6566baf1ef330f636ab7b9d70f4f.tar.gz | |
Add some DIAGNOSTIC code.
While in userland, keep the thread's ucred reference in a shadow
field so that the usual place to store it is NULL.
If DIAGNOSTIC is not set, the thread ucred is kept valid until the next
kernel entry, at which time it is checked against the process cred
and possibly corrected. Produces a BIG speedup in
kernels with INVARIANTS set. (A previous commit corrected it
for the non INVARIANTS case already)
Reviewed by: dillon@freebsd.org
Diffstat (limited to 'sys/kern/kern_fork.c')
| -rw-r--r-- | sys/kern/kern_fork.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c index 3cd3017..8fe1006 100644 --- a/sys/kern/kern_fork.c +++ b/sys/kern/kern_fork.c @@ -477,6 +477,9 @@ again: PROC_LOCK(p1); p2->p_ucred = crhold(p1->p_ucred); td2->td_ucred = crhold(p2->p_ucred); /* XXXKSE */ +#ifdef DIAGNOSTIC /* see the comment in ast() */ + td2->td_ucred_cache = NULL; +#endif if (p2->p_args) p2->p_args->ar_ref++; @@ -802,12 +805,12 @@ fork_exit(callout, arg, frame) kthread_exit(0); } PROC_UNLOCK(p); -#ifdef INVARIANTS - mtx_lock(&Giant); - crfree(td->td_ucred); - mtx_unlock(&Giant); - td->td_ucred = NULL; -#endif +#ifdef DIAGNOSTIC /* see the comment in ast() */ + if (td->td_ucred_cache) + panic("fork_exit:thread already has cached ucred"); + td->td_ucred_cache = td->td_ucred; + td->td_ucred = NULL; +#endif /* DIAGNOSTIC */ mtx_assert(&Giant, MA_NOTOWNED); } |
