[PATCH] rcu: don't include <linux/ktime.h> in rcutiny.h

[PATCH] rcu: don't include <linux/ktime.h> in rcutiny.h

[Christoph Hellwig]

The kbuild reported a built failure due to a header loop when RCUTINY is
enabled with my pending riscv-nommu port.  Switch rcutiny.h to only
include the minimal required header to get HZ instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/rcutiny.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 8e727f57d814..9bf1dfe7781f 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -12,7 +12,7 @@
 #ifndef __LINUX_TINY_H
 #define __LINUX_TINY_H
 
-#include <linux/ktime.h>
+#include <asm/param.h> /* for HZ */
 
 /* Never flag non-existent other CPUs! */
 static inline bool rcu_eqs_special_set(int cpu) { return false; }
-- 
2.20.1

Re: [PATCH] rcu: don't include <linux/ktime.h> in rcutiny.h

[Paul E. McKenney]

On Thu, Aug 22, 2019 at 10:53:43AM +0900, Christoph Hellwig wrote:
> The kbuild reported a built failure due to a header loop when RCUTINY is
> enabled with my pending riscv-nommu port.  Switch rcutiny.h to only
> include the minimal required header to get HZ instead.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Queued for review and testing, thank you!

Do you need this in v5.4?  My normal workflow would put it into v5.5.

							Thanx, Paul

> ---
>  include/linux/rcutiny.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
> index 8e727f57d814..9bf1dfe7781f 100644
> --- a/include/linux/rcutiny.h
> +++ b/include/linux/rcutiny.h
> @@ -12,7 +12,7 @@
>  #ifndef __LINUX_TINY_H
>  #define __LINUX_TINY_H
>  
> -#include <linux/ktime.h>
> +#include <asm/param.h> /* for HZ */
>  
>  /* Never flag non-existent other CPUs! */
>  static inline bool rcu_eqs_special_set(int cpu) { return false; }
> -- 
> 2.20.1
> 

Re: [PATCH] rcu: don't include <linux/ktime.h> in rcutiny.h

[Christoph Hellwig]

On Wed, Aug 21, 2019 at 08:02:00PM -0700, Paul E. McKenney wrote:
> On Thu, Aug 22, 2019 at 10:53:43AM +0900, Christoph Hellwig wrote:
> > The kbuild reported a built failure due to a header loop when RCUTINY is
> > enabled with my pending riscv-nommu port.  Switch rcutiny.h to only
> > include the minimal required header to get HZ instead.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Queued for review and testing, thank you!
> 
> Do you need this in v5.4?  My normal workflow would put it into v5.5.

I hope the riscv-nommu coe gets merges for 5.4, so if we could queue
it up for that I'd appreciate it.

Re: [PATCH] rcu: don't include <linux/ktime.h> in rcutiny.h

[Paul E. McKenney]

On Thu, Aug 22, 2019 at 05:48:41AM +0200, Christoph Hellwig wrote:
> On Wed, Aug 21, 2019 at 08:02:00PM -0700, Paul E. McKenney wrote:
> > On Thu, Aug 22, 2019 at 10:53:43AM +0900, Christoph Hellwig wrote:
> > > The kbuild reported a built failure due to a header loop when RCUTINY is
> > > enabled with my pending riscv-nommu port.  Switch rcutiny.h to only
> > > include the minimal required header to get HZ instead.
> > > 
> > > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > 
> > Queued for review and testing, thank you!
> > 
> > Do you need this in v5.4?  My normal workflow would put it into v5.5.
> 
> I hope the riscv-nommu coe gets merges for 5.4, so if we could queue
> it up for that I'd appreciate it.

OK, it did pass rcutorture's various !SMP scenarios, so this seems
plausible.

I am sending my main pull request today, but will also put this patch
where 0day and -next can see it.  If it does OK with that and with
additional review/testing for a few days, I will send a second pull
request with that patch some time next week.

							Thanx, Paul