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11909 THREAD_KPRI_RELEASE does nothing of the sort
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
@@ -19,14 +19,13 @@
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
+ * Copyright 2019 Joyent, Inc.
*/
-#pragma ident "%Z%%M% %I% %E% SMI"
-
#if defined(lint)
#include <sys/types.h>
#include <sys/thread.h>
#include <sys/cpuvar.h>
#else /* lint */
@@ -500,14 +499,11 @@
.align 16
ENTRY(rw_enter)
cmp %o1, RW_WRITER ! entering as writer?
be,a,pn %icc, 2f ! if so, go do it ...
or THREAD_REG, RW_WRITE_LOCKED, %o5 ! delay: %o5 = owner
- ld [THREAD_REG + T_KPRI_REQ], %o3 ! begin THREAD_KPRI_REQUEST()
ldn [%o0], %o4 ! %o4 = old lock value
- inc %o3 ! bump kpri
- st %o3, [THREAD_REG + T_KPRI_REQ] ! store new kpri
1:
andcc %o4, RW_WRITE_CLAIMED, %g0 ! write-locked or write-wanted?
bz,pt %xcc, 3f ! if so, prepare to block
add %o4, RW_READ_LOCK, %o5 ! delay: increment hold count
sethi %hi(rw_enter_sleep), %o2 ! load up jump
@@ -550,19 +546,18 @@
membar #LoadStore|#StoreStore ! membar_exit()
subcc %o4, RW_READ_LOCK, %o5 ! %o5 = new lock value if reader
bnz,pn %xcc, 2f ! single reader, no waiters?
clr %o1
1:
- ld [THREAD_REG + T_KPRI_REQ], %g1 ! begin THREAD_KPRI_RELEASE()
srl %o4, RW_HOLD_COUNT_SHIFT, %o3 ! %o3 = hold count (lockstat)
casx [%o0], %o4, %o5 ! try to drop lock
cmp %o4, %o5 ! did we succeed?
bne,pn %xcc, rw_exit_wakeup ! if not, go to C
- dec %g1 ! delay: drop kpri
+ nop ! delay: do nothing
.rw_read_exit_lockstat_patch_point:
retl
- st %g1, [THREAD_REG + T_KPRI_REQ] ! delay: store new kpri
+ nop ! delay: do nothing
2:
andcc %o4, RW_WRITE_LOCKED, %g0 ! are we a writer?
bnz,a,pt %xcc, 3f
or THREAD_REG, RW_WRITE_LOCKED, %o4 ! delay: %o4 = owner
cmp %o5, RW_READ_LOCK ! would lock still be held?