Hi,
A patch to eliminate the semaphore in the perfmon driver. I believe
Stephane also already applied this to his private tree.
Cheers,
Jes
Migrate perfmon from using an old semaphore to a completion handler.
Signed-off-by: Jes Sorensen <[email protected]>
----
arch/ia64/kernel/perfmon.c | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)
Index: linux-2.6/arch/ia64/kernel/perfmon.c
===================================================================
--- linux-2.6.orig/arch/ia64/kernel/perfmon.c
+++ linux-2.6/arch/ia64/kernel/perfmon.c
@@ -39,6 +39,7 @@
#include <linux/mount.h>
#include <linux/bitops.h>
#include <linux/rcupdate.h>
+#include <linux/completion.h>
#include <asm/errno.h>
#include <asm/intrinsics.h>
@@ -285,7 +286,7 @@
unsigned long ctx_ovfl_regs[4]; /* which registers overflowed (notification) */
- struct semaphore ctx_restart_sem; /* use for blocking notification mode */
+ struct completion ctx_restart_done; /* use for blocking notification mode */
unsigned long ctx_used_pmds[4]; /* bitmask of PMD used */
unsigned long ctx_all_pmds[4]; /* bitmask of all accessible PMDs */
@@ -1988,7 +1989,7 @@
/*
* force task to wake up from MASKED state
*/
- up(&ctx->ctx_restart_sem);
+ complete(&ctx->ctx_restart_done);
DPRINT(("waking up ctx_state=%d\n", state));
@@ -2703,7 +2704,7 @@
/*
* init restart semaphore to locked
*/
- sema_init(&ctx->ctx_restart_sem, 0);
+ init_completion(&ctx->ctx_restart_done);
/*
* activation is used in SMP only
@@ -3684,7 +3685,7 @@
*/
if (CTX_OVFL_NOBLOCK(ctx) == 0 && state == PFM_CTX_MASKED) {
DPRINT(("unblocking [%d] \n", task->pid));
- up(&ctx->ctx_restart_sem);
+ complete(&ctx->ctx_restart_done);
} else {
DPRINT(("[%d] armed exit trap\n", task->pid));
@@ -5086,7 +5087,7 @@
* may go through without blocking on SMP systems
* if restart has been received already by the time we call down()
*/
- ret = down_interruptible(&ctx->ctx_restart_sem);
+ ret = wait_for_completion_interruptible(&ctx->ctx_restart_done);
DPRINT(("after block sleeping ret=%d\n", ret));