diff options
author | bmilekic <bmilekic@FreeBSD.org> | 2001-01-19 01:59:14 +0000 |
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committer | bmilekic <bmilekic@FreeBSD.org> | 2001-01-19 01:59:14 +0000 |
commit | 37decc93f5a2dfb49438d1e77245218780583ef6 (patch) | |
tree | 2e4b859fb1993ec2fe69e3e946d14a9fdc9cf441 /sys/kern/subr_witness.c | |
parent | 5977e97236d57a51dc2ddf0634bb4a69d30dc36f (diff) | |
download | FreeBSD-src-37decc93f5a2dfb49438d1e77245218780583ef6.zip FreeBSD-src-37decc93f5a2dfb49438d1e77245218780583ef6.tar.gz |
Implement MTX_RECURSE flag for mtx_init().
All calls to mtx_init() for mutexes that recurse must now include
the MTX_RECURSE bit in the flag argument variable. This change is in
preparation for an upcoming (further) mutex API cleanup.
The witness code will call panic() if a lock is found to recurse but
the MTX_RECURSE bit was not set during the lock's initialization.
The old MTX_RECURSE "state" bit (in mtx_lock) has been renamed to
MTX_RECURSED, which is more appropriate given its meaning.
The following locks have been made "recursive," thus far:
eventhandler, Giant, callout, sched_lock, possibly some others declared
in the architecture-specific code, all of the network card driver locks
in pci/, as well as some other locks in dev/ stuff that I've found to
be recursive.
Reviewed by: jhb
Diffstat (limited to 'sys/kern/subr_witness.c')
-rw-r--r-- | sys/kern/subr_witness.c | 75 |
1 files changed, 55 insertions, 20 deletions
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c index a79299c..da8f197 100644 --- a/sys/kern/subr_witness.c +++ b/sys/kern/subr_witness.c @@ -259,7 +259,7 @@ mtx_enter_hard(struct mtx *m, int type, int saveintr) case MTX_DEF: if ((m->mtx_lock & MTX_FLAGMASK) == (uintptr_t)p) { m->mtx_recurse++; - atomic_set_ptr(&m->mtx_lock, MTX_RECURSE); + atomic_set_ptr(&m->mtx_lock, MTX_RECURSED); if ((type & MTX_QUIET) == 0) CTR1(KTR_LOCK, "mtx_enter: 0x%p recurse", m); return; @@ -434,9 +434,9 @@ mtx_exit_hard(struct mtx *m, int type) switch (type) { case MTX_DEF: case MTX_DEF | MTX_NOSWITCH: - if (m->mtx_recurse != 0) { + if (mtx_recursed(m)) { if (--(m->mtx_recurse) == 0) - atomic_clear_ptr(&m->mtx_lock, MTX_RECURSE); + atomic_clear_ptr(&m->mtx_lock, MTX_RECURSED); if ((type & MTX_QUIET) == 0) CTR1(KTR_LOCK, "mtx_exit: 0x%p unrecurse", m); return; @@ -501,7 +501,7 @@ mtx_exit_hard(struct mtx *m, int type) break; case MTX_SPIN: case MTX_SPIN | MTX_FIRST: - if (m->mtx_recurse != 0) { + if (mtx_recursed(m)) { m->mtx_recurse--; return; } @@ -515,7 +515,7 @@ mtx_exit_hard(struct mtx *m, int type) } break; case MTX_SPIN | MTX_TOPHALF: - if (m->mtx_recurse != 0) { + if (mtx_recursed(m)) { m->mtx_recurse--; return; } @@ -655,7 +655,7 @@ mtx_destroy(struct mtx *m) if (!mtx_owned(m)) { MPASS(m->mtx_lock == MTX_UNOWNED); } else { - MPASS((m->mtx_lock & (MTX_RECURSE|MTX_CONTESTED)) == 0); + MPASS((m->mtx_lock & (MTX_RECURSED|MTX_CONTESTED)) == 0); } mtx_validate(m, MV_DESTROY); /* diagnostic */ #endif @@ -701,8 +701,9 @@ struct witness { u_char w_Giant_squawked:1; u_char w_other_squawked:1; u_char w_same_squawked:1; - u_char w_sleep:1; - u_char w_spin:1; /* this is a spin mutex */ + u_char w_sleep:1; /* MTX_DEF type mutex. */ + u_char w_spin:1; /* MTX_SPIN type mutex. */ + u_char w_recurse:1; /* MTX_RECURSE mutex option. */ u_int w_level; struct witness *w_children[WITNESS_NCHILDREN]; }; @@ -838,11 +839,16 @@ witness_enter(struct mtx *m, int flags, const char *file, int line) p = CURPROC; if (flags & MTX_SPIN) { - if (!w->w_spin) + if (!(w->w_spin)) panic("mutex_enter: MTX_SPIN on MTX_DEF mutex %s @" " %s:%d", m->mtx_description, file, line); - if (m->mtx_recurse != 0) + if (mtx_recursed(m)) { + if (!(w->w_recurse)) + panic("mutex_enter: recursion on non-recursive" + " mutex %s @ %s:%d", m->mtx_description, + file, line); return; + } mtx_enter(&w_mtx, MTX_SPIN | MTX_QUIET); i = PCPU_GET(witness_spin_check); if (i != 0 && w->w_level < i) { @@ -864,8 +870,13 @@ witness_enter(struct mtx *m, int flags, const char *file, int line) panic("mutex_enter: MTX_DEF on MTX_SPIN mutex %s @ %s:%d", m->mtx_description, file, line); - if (m->mtx_recurse != 0) + if (mtx_recursed(m)) { + if (!(w->w_recurse)) + panic("mutex_enter: recursion on non-recursive" + " mutex %s @ %s:%d", m->mtx_description, + file, line); return; + } if (witness_dead) goto out; if (cold) @@ -971,11 +982,16 @@ witness_exit(struct mtx *m, int flags, const char *file, int line) w = m->mtx_witness; if (flags & MTX_SPIN) { - if (!w->w_spin) + if (!(w->w_spin)) panic("mutex_exit: MTX_SPIN on MTX_DEF mutex %s @" " %s:%d", m->mtx_description, file, line); - if (m->mtx_recurse != 0) + if (mtx_recursed(m)) { + if (!(w->w_recurse)) + panic("mutex_exit: recursion on non-recursive" + " mutex %s @ %s:%d", m->mtx_description, + file, line); return; + } mtx_enter(&w_mtx, MTX_SPIN | MTX_QUIET); PCPU_SET(witness_spin_check, PCPU_GET(witness_spin_check) & ~w->w_level); @@ -986,8 +1002,13 @@ witness_exit(struct mtx *m, int flags, const char *file, int line) panic("mutex_exit: MTX_DEF on MTX_SPIN mutex %s @ %s:%d", m->mtx_description, file, line); - if (m->mtx_recurse != 0) + if (mtx_recursed(m)) { + if (!(w->w_recurse)) + panic("mutex_exit: recursion on non-recursive" + " mutex %s @ %s:%d", m->mtx_description, + file, line); return; + } if ((flags & MTX_NOSWITCH) == 0 && !mtx_legal2block() && !cold) panic("switchable mtx_exit() of %s when not legal @ %s:%d", @@ -1005,12 +1026,17 @@ witness_try_enter(struct mtx *m, int flags, const char *file, int line) if (panicstr) return; if (flags & MTX_SPIN) { - if (!w->w_spin) + if (!(w->w_spin)) panic("mutex_try_enter: " "MTX_SPIN on MTX_DEF mutex %s @ %s:%d", m->mtx_description, file, line); - if (m->mtx_recurse != 0) + if (mtx_recursed(m)) { + if (!(w->w_recurse)) + panic("mutex_try_enter: recursion on" + " non-recursive mutex %s @ %s:%d", + m->mtx_description, file, line); return; + } mtx_enter(&w_mtx, MTX_SPIN | MTX_QUIET); PCPU_SET(witness_spin_check, PCPU_GET(witness_spin_check) | w->w_level); @@ -1026,9 +1052,13 @@ witness_try_enter(struct mtx *m, int flags, const char *file, int line) panic("mutex_try_enter: MTX_DEF on MTX_SPIN mutex %s @ %s:%d", m->mtx_description, file, line); - if (m->mtx_recurse != 0) + if (mtx_recursed(m)) { + if (!(w->w_recurse)) + panic("mutex_try_enter: recursion on non-recursive" + " mutex %s @ %s:%d", m->mtx_description, file, + line); return; - + } w->w_file = file; w->w_line = line; m->mtx_line = line; @@ -1156,7 +1186,12 @@ enroll(const char *description, int flag) if (*order == NULL) panic("spin lock %s not in order list", description); w->w_level = i; - } + } else + w->w_sleep = 1; + + if (flag & MTX_RECURSE) + w->w_recurse = 1; + return (w); } @@ -1270,7 +1305,7 @@ witness_levelall (void) struct witness *w, *w1; for (w = w_all; w; w = w->w_next) - if (!w->w_spin) + if (!(w->w_spin)) w->w_level = 0; for (w = w_all; w; w = w->w_next) { if (w->w_spin) |