Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1213142

Re: h8300 build failures in linux-next (in rcu code, gcc 5.x related, not limited to h8300)

Show all headers | View raw

On 08/25, Guenter Roeck wrote:
>
> Hi Mark,
>
> On 08/25/2015 07:27 AM, Mark Salter wrote:
>> On Tue, 2015-08-25 at 14:56 +0900, Yoshinori Sato wrote:
>>> On Tue, 25 Aug 2015 03:34:20 +0900,
>>> Guenter Roeck wrote:
>>>>
>>>> Hi,
>>>>
>>>> In linux-next as of today (0824), all h8300 builds fail for me with an
>>>> internal
>>>> compiler error.
>>>>
>>>> Building h8300:allnoconfig ... failed
>>>> --------------
>>>> Error log:
>>>>
>>>> In file included from include/linux/rcupdate.h:429:0,
>>>>                   from include/linux/rcusync.h:5,
>>>>                   from kernel/rcu/sync.c:1:
>>>> include/linux/rcutiny.h: In function ‘rcu_barrier_sched’:
>>>> include/linux/rcutiny.h:55:20: internal compiler error: Segmentation
>>>> fault
>>>>   static inline void rcu_barrier_sched(void)
>>>>                      ^
>>>>
>>>> I tried both gcc 5.1 and 5.2, built with the patch set available to me.
>>>>
>>>> Is there a more recent compiler / patch set available that might fix
>>>> the problem ?
>>>>
>>>
>>> No.
>>> I tried gcc 6.0. It got same error.
>>> It looks optimization problem on h8300 target.
>>> I will investigate it.
>>
>> I get the same ICE with c6x gcc 5.1
>>
>
> Interesting. h8300 was the only gcc 5+ compiler I had used so far.
> Just for fun, I built an alpha toolchain with gcc 5.1. Same problem there.
> So it looks like it isn't a h8300 problem after all, it is a gcc problem.
>
> Updated subject line, and copied rcu maintainers.

Damn. This was caused by my patch, I need to react, and I do not know
what to say ;)

OK, this is gcc bug. But we probably need the workaround, and I don't
have a h8300 machine so I can't test the fix.

Could you please try to compile kernel/rcu/sync.o with the patch below?
Just to know how "stable" this bug is. I expect the compilation should
fail again, rcutiny.h:rcu_barrier() is "inline" too.

Oleg.


--- a/kernel/rcu/sync.c
+++ b/kernel/rcu/sync.c
@@ -24,7 +24,6 @@ static const struct {
 	[RCU_SCHED_SYNC] = {
 		.sync = synchronize_sched,
 		.call = call_rcu_sched,
-		.wait = rcu_barrier_sched,
 		__INIT_HELD(rcu_read_lock_sched_held)
 	},
 	[RCU_BH_SYNC] = {

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

h8300 build failures ijn linux-next Guenter Roeck <linux@roeck-us.net> - 2015-08-24 20:40 +0200
  Re: h8300 build failures ijn linux-next Yoshinori Sato <ysato@users.sourceforge.jp> - 2015-08-25 08:00 +0200
    Re: h8300 build failures ijn linux-next Mark Salter <msalter@redhat.com> - 2015-08-25 16:30 +0200
      Re: h8300 build failures in linux-next (in rcu code, gcc 5.x related,  not limited to h8300) Guenter Roeck <linux@roeck-us.net> - 2015-08-25 17:10 +0200
        Re: h8300 build failures in linux-next (in rcu code, gcc 5.x  related, not limited to h8300) Oleg Nesterov <oleg@redhat.com> - 2015-08-25 18:20 +0200
          Re: h8300 build failures in linux-next (in rcu code, gcc 5.x  related, not limited to h8300) Oleg Nesterov <oleg@redhat.com> - 2015-08-25 18:30 +0200
        Re: h8300 build failures in linux-next (in rcu code, gcc 5.x related, not limited to h8300) Yoshinori Sato <ysato@users.sourceforge.jp> - 2015-08-25 19:00 +0200
          Re: h8300 build failures in linux-next (in rcu code, gcc 5.x  related, not limited to h8300) Oleg Nesterov <oleg@redhat.com> - 2015-08-25 19:40 +0200
            Re: h8300 build failures in linux-next (in rcu code, gcc 5.x  related, not limited to h8300) Oleg Nesterov <oleg@redhat.com> - 2015-08-25 20:10 +0200
              Re: h8300 build failures in linux-next (in rcu code, gcc 5.x  related, not limited to h8300) Mark Salter <msalter@redhat.com> - 2015-08-25 20:20 +0200
        [PATCH] rcu: change _wait_rcu_gp() to work around gcc 67055 bug Oleg Nesterov <oleg@redhat.com> - 2015-08-25 20:50 +0200
          Re: [PATCH] rcu: change _wait_rcu_gp() to work around gcc 67055 bug "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-08-25 21:10 +0200
          Re: [PATCH] rcu: change _wait_rcu_gp() to work around gcc 67055 bug Oleg Nesterov <oleg@redhat.com> - 2015-08-25 21:10 +0200

csiph-web