Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=960c65e88452e761e257c6a20062c91c3e7fa5ac
Commit:     960c65e88452e761e257c6a20062c91c3e7fa5ac
Parent:     9216f194e4b1a967996f0335cfe2ac42df4438b7
Author:     Peter Zijlstra <[EMAIL PROTECTED]>
AuthorDate: Thu Feb 7 15:01:26 2008 +0900
Committer:  Paul Mundt <[EMAIL PROTECTED]>
CommitDate: Thu Feb 14 14:22:08 2008 +0900

    sh: fix xtime_lock deadlocking.
    
    move update_process_times() out from under xtime_lock.
    
    Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
    Signed-off-by: Paul Mundt <[EMAIL PROTECTED]>
---
 arch/sh/kernel/time_32.c |   19 +++++++++++++++----
 arch/sh/kernel/time_64.c |   31 +++++++++++++++++--------------
 2 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/arch/sh/kernel/time_32.c b/arch/sh/kernel/time_32.c
index 2bc04bf..7281342 100644
--- a/arch/sh/kernel/time_32.c
+++ b/arch/sh/kernel/time_32.c
@@ -120,10 +120,6 @@ static long last_rtc_update;
  */
 void handle_timer_tick(void)
 {
-       do_timer(1);
-#ifndef CONFIG_SMP
-       update_process_times(user_mode(get_irq_regs()));
-#endif
        if (current->pid)
                profile_tick(CPU_PROFILING);
 
@@ -133,6 +129,16 @@ void handle_timer_tick(void)
 #endif
 
        /*
+        * Here we are in the timer irq handler. We just have irqs locally
+        * disabled but we don't know if the timer_bh is running on the other
+        * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
+        * the irq version of write_lock because as just said we have irq
+        * locally disabled. -arca
+        */
+       write_seqlock(&xtime_lock);
+       do_timer(1);
+
+       /*
         * If we have an externally synchronized Linux clock, then update
         * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
         * called as close as possible to 500 ms before the new second starts.
@@ -147,6 +153,11 @@ void handle_timer_tick(void)
                        /* do it again in 60s */
                        last_rtc_update = xtime.tv_sec - 600;
        }
+       write_sequnlock(&xtime_lock);
+
+#ifndef CONFIG_SMP
+       update_process_times(user_mode(get_irq_regs()));
+#endif
 }
 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 
diff --git a/arch/sh/kernel/time_64.c b/arch/sh/kernel/time_64.c
index f819ba3..898977e 100644
--- a/arch/sh/kernel/time_64.c
+++ b/arch/sh/kernel/time_64.c
@@ -229,15 +229,22 @@ static long last_rtc_update;
 static inline void do_timer_interrupt(void)
 {
        unsigned long long current_ctc;
+
+       if (current->pid)
+               profile_tick(CPU_PROFILING);
+
+       /*
+        * Here we are in the timer irq handler. We just have irqs locally
+        * disabled but we don't know if the timer_bh is running on the other
+        * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
+        * the irq version of write_lock because as just said we have irq
+        * locally disabled. -arca
+        */
+       write_lock(&xtime_lock);
        asm ("getcon cr62, %0" : "=r" (current_ctc));
        ctc_last_interrupt = (unsigned long) current_ctc;
 
        do_timer(1);
-#ifndef CONFIG_SMP
-       update_process_times(user_mode(get_irq_regs()));
-#endif
-       if (current->pid)
-               profile_tick(CPU_PROFILING);
 
 #ifdef CONFIG_HEARTBEAT
        if (sh_mv.mv_heartbeat != NULL)
@@ -259,6 +266,11 @@ static inline void do_timer_interrupt(void)
                        /* do it again in 60 s */
                        last_rtc_update = xtime.tv_sec - 600;
        }
+       write_unlock(&xtime_lock);
+
+#ifndef CONFIG_SMP
+       update_process_times(user_mode(get_irq_regs()));
+#endif
 }
 
 /*
@@ -275,16 +287,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
        timer_status &= ~0x100;
        ctrl_outw(timer_status, TMU0_TCR);
 
-       /*
-        * Here we are in the timer irq handler. We just have irqs locally
-        * disabled but we don't know if the timer_bh is running on the other
-        * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
-        * the irq version of write_lock because as just said we have irq
-        * locally disabled. -arca
-        */
-       write_lock(&xtime_lock);
        do_timer_interrupt();
-       write_unlock(&xtime_lock);
 
        return IRQ_HANDLED;
 }
-
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