Thread (7 messages) flat view 7 messages, 3 authors, 2012-11-09
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[PATCH 2/4] arm64: Fix the update_vsyscall() prototype

From: John Stultz <hidden>
Date: 2012-11-09 22:47:54

On 10/16/2012 09:46 AM, Catalin Marinas wrote:
quoted hunk ↗ jump to hunk
With commit 576094b7 (time: Introduce new GENERIC_TIME_VSYSCALL) the old
update_vsyscall() prototype is no longer available. This patch updates
the arm64 port.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <redacted>
Cc: John Stultz <redacted>
---
  arch/arm64/kernel/vdso.c | 20 ++++++++++----------
  1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 17948fc..ba45794 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -28,6 +28,7 @@
  #include <linux/sched.h>
  #include <linux/signal.h>
  #include <linux/slab.h>
+#include <linux/timekeeper_internal.h>
  #include <linux/vmalloc.h>
  
  #include <asm/cacheflush.h>
@@ -222,11 +223,10 @@ struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
  /*
   * Update the vDSO data page to keep in sync with kernel timekeeping.
   */
-void update_vsyscall(struct timespec *ts, struct timespec *wtm,
-		     struct clocksource *clock, u32 mult)
+void update_vsyscall(struct timekeeper *tk)
  {
  	struct timespec xtime_coarse;
-	u32 use_syscall = strcmp(clock->name, "arch_sys_counter");
+	u32 use_syscall = strcmp(tk->clock->name, "arch_sys_counter");
  
  	++vdso_data->tb_seq_count;
  	smp_wmb();
@@ -237,13 +237,13 @@ void update_vsyscall(struct timespec *ts, struct timespec *wtm,
  	vdso_data->xtime_coarse_nsec		= xtime_coarse.tv_nsec;
  
  	if (!use_syscall) {
-		vdso_data->cs_cycle_last	= clock->cycle_last;
-		vdso_data->xtime_clock_sec	= ts->tv_sec;
-		vdso_data->xtime_clock_nsec	= ts->tv_nsec;
-		vdso_data->cs_mult		= mult;
-		vdso_data->cs_shift		= clock->shift;
-		vdso_data->wtm_clock_sec	= wtm->tv_sec;
-		vdso_data->wtm_clock_nsec	= wtm->tv_nsec;
+		vdso_data->cs_cycle_last	= tk->clock->cycle_last;
+		vdso_data->xtime_clock_sec	= tk->xtime_sec;
+		vdso_data->xtime_clock_nsec	= tk->xtime_nsec >> tk->shift;
Sorry for the collision here!

One word of warning:  Truncating the sub-ns base like this can cause 
small single ns inconsistencies from the vsyscalls.

So either use GENERIC_TIME_VSYSCALL_OLD to enable the 1ns generic 
rounding-up code, or rework the vsyscall code to use the sub-ns 
granularity as done in 650ea02475106e8d6bdf561896d2ffe0d1c0ebb4 for 
x86_64.  I hope to drop the _OLD config eventually, so this will need to 
be done at some point.

thanks
-john
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