[PATCH] ia64 TS_RESTORE_SIGMASK

From: Roland McGrath
Date: Wed Apr 30 2008 - 17:40:36 EST


Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define
our own set_restore_sigmask() function. This saves the costly
SMP-safe set_bit operation, which we do not need for the sigmask
flag since TIF_SIGPENDING always has to be set too.

Signed-off-by: Roland McGrath <roland@xxxxxxxxxx>
---
arch/ia64/ia32/ia32_signal.c | 2 +-
arch/ia64/kernel/signal.c | 15 ++++++++-------
include/asm-ia64/thread_info.h | 13 +++++++++++--
3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/arch/ia64/ia32/ia32_signal.c b/arch/ia64/ia32/ia32_signal.c
index 256a7fa..b763ca1 100644
--- a/arch/ia64/ia32/ia32_signal.c
+++ b/arch/ia64/ia32/ia32_signal.c
@@ -463,7 +463,7 @@ sys32_sigsuspend (int history0, int history1, old_sigset_t mask)

current->state = TASK_INTERRUPTIBLE;
schedule();
- set_thread_flag(TIF_RESTORE_SIGMASK);
+ set_restore_sigmask();
return -ERESTARTNOHAND;
}

diff --git a/arch/ia64/kernel/signal.c b/arch/ia64/kernel/signal.c
index 5740296..19c5a78 100644
--- a/arch/ia64/kernel/signal.c
+++ b/arch/ia64/kernel/signal.c
@@ -464,7 +464,7 @@ ia64_do_signal (struct sigscratch *scr, long in_syscall)
if (!user_mode(&scr->pt))
return;

- if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ if (current_thread_info()->status & TS_RESTORE_SIGMASK)
oldset = &current->saved_sigmask;
else
oldset = &current->blocked;
@@ -530,12 +530,13 @@ ia64_do_signal (struct sigscratch *scr, long in_syscall)
* continue to iterate in this loop so we can deliver the SIGSEGV...
*/
if (handle_signal(signr, &ka, &info, oldset, scr)) {
- /* a signal was successfully delivered; the saved
+ /*
+ * A signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
* and will be restored by sigreturn, so we can simply
- * clear the TIF_RESTORE_SIGMASK flag */
- if (test_thread_flag(TIF_RESTORE_SIGMASK))
- clear_thread_flag(TIF_RESTORE_SIGMASK);
+ * clear the TS_RESTORE_SIGMASK flag.
+ */
+ current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
return;
}
}
@@ -566,8 +567,8 @@ ia64_do_signal (struct sigscratch *scr, long in_syscall)

/* if there's no signal to deliver, we just put the saved sigmask
* back */
- if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
- clear_thread_flag(TIF_RESTORE_SIGMASK);
+ if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
+ current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
}
}
diff --git a/include/asm-ia64/thread_info.h b/include/asm-ia64/thread_info.h
index f30e055..2422ac6 100644
--- a/include/asm-ia64/thread_info.h
+++ b/include/asm-ia64/thread_info.h
@@ -108,13 +108,11 @@ extern void tsk_clear_notify_resume(struct task_struct *tsk);
#define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */
#define TIF_FREEZE 20 /* is freezing for suspend */
#define TIF_RESTORE_RSE 21 /* user RBS is newer than kernel RBS */
-#define TIF_RESTORE_SIGMASK 22 /* restore signal mask in do_signal() */

#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_SYSCALL_TRACEAUDIT (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP)
-#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
@@ -131,7 +129,18 @@ extern void tsk_clear_notify_resume(struct task_struct *tsk);
#define TIF_WORK_MASK (TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))

#define TS_POLLING 1 /* true if in idle loop and not sleeping */
+#define TS_RESTORE_SIGMASK 2 /* restore signal mask in do_signal() */

#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)

+#ifndef __ASSEMBLY__
+#define HAVE_SET_RESTORE_SIGMASK 1
+static inline void set_restore_sigmask(void)
+{
+ struct thread_info *ti = current_thread_info();
+ ti->status |= TS_RESTORE_SIGMASK;
+ set_bit(TIF_SIGPENDING, &ti->flags);
+}
+#endif /* !__ASSEMBLY__ */
+
#endif /* _ASM_IA64_THREAD_INFO_H */
--
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