sys_rt_sigreturn calling sys_futex?

[Ivan Novick]

Hello,

I have a userspace app that I profiled using SystemTap.

It says there are frequent calls to sys_futex which come from sys_rt_sigreturn.

It is true, that my app has many signal handler calls due to
frequently set timers in the code.

I had a look at the source for my kernel: Suse: linux-2.6.27.39-0.3
but I don't see any calls to futex from inside sys_rt_sigreturn.

Do you know if sys_rt_sigreturn is somehow calling sys_futex?

And if so, does this imply that ultra-frequent signal handling can
create a bottleneck between many processes in the sys_rt_sigreturn
system call trying to access a futex?

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