[PATCH RESEND] sgi-gru: use time_before()

[PATCH RESEND] sgi-gru: use time_before()

[Manuel Schölling]

To be future-proof and for better readability the time comparisons are
modified to use time_before() instead of plain, error-prone math.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
---
 drivers/misc/sgi-gru/grumain.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
index ae16c8c..1525870 100644
--- a/drivers/misc/sgi-gru/grumain.c
+++ b/drivers/misc/sgi-gru/grumain.c
@@ -930,6 +930,7 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct gru_thread_state *gts;
 	unsigned long paddr, vaddr;
+	unsigned long expires;
 
 	vaddr = (unsigned long)vmf->virtual_address;
 	gru_dbg(grudev, "vma %p, vaddr 0x%lx (0x%lx)\n",
@@ -954,7 +955,8 @@ again:
 			mutex_unlock(&gts->ts_ctxlock);
 			set_current_state(TASK_INTERRUPTIBLE);
 			schedule_timeout(GRU_ASSIGN_DELAY);  /* true hack ZZZ */
-			if (gts->ts_steal_jiffies + GRU_STEAL_DELAY < jiffies)
+			expires = gts->ts_steal_jiffies + GRU_STEAL_DELAY;
+			if (time_before(expires, jiffies))
 				gru_steal_context(gts);
 			goto again;
 		}
-- 
1.7.10.4

Re: [PATCH RESEND] sgi-gru: use time_before()

[Dimitri Sivanich]

Acked-by: Dimitri Sivanich <sivanich@sgi.com>

On Fri, May 30, 2014 at 03:40:59PM +0200, Manuel Schölling wrote:
> To be future-proof and for better readability the time comparisons are
> modified to use time_before() instead of plain, error-prone math.
> 
> Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
> ---
>  drivers/misc/sgi-gru/grumain.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
> index ae16c8c..1525870 100644
> --- a/drivers/misc/sgi-gru/grumain.c
> +++ b/drivers/misc/sgi-gru/grumain.c
> @@ -930,6 +930,7 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
>  	struct gru_thread_state *gts;
>  	unsigned long paddr, vaddr;
> +	unsigned long expires;
>  
>  	vaddr = (unsigned long)vmf->virtual_address;
>  	gru_dbg(grudev, "vma %p, vaddr 0x%lx (0x%lx)\n",
> @@ -954,7 +955,8 @@ again:
>  			mutex_unlock(&gts->ts_ctxlock);
>  			set_current_state(TASK_INTERRUPTIBLE);
>  			schedule_timeout(GRU_ASSIGN_DELAY);  /* true hack ZZZ */
> -			if (gts->ts_steal_jiffies + GRU_STEAL_DELAY < jiffies)
> +			expires = gts->ts_steal_jiffies + GRU_STEAL_DELAY;
> +			if (time_before(expires, jiffies))
>  				gru_steal_context(gts);
>  			goto again;
>  		}
> -- 
> 1.7.10.4