From: Grygorii Strashko <grygorii.strashko@ti.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
linux-rt-users <linux-rt-users@vger.kernel.org>
Subject: Re: [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port
Date: Mon, 25 Jan 2016 19:14:05 +0200 [thread overview]
Message-ID: <56A657DD.8080602@ti.com> (raw)
In-Reply-To: <20160122204018.GA3883@linutronix.de>
On 01/22/2016 10:40 PM, Sebastian Andrzej Siewior wrote:
> * Sebastian Andrzej Siewior | 2016-01-22 13:54:43 [+0100]:
>
>>> Should _TIF_WORK_MASK also contain _TIF_NEED_RESCHED_LAZY?
>>
>> Yes, and arm64 lacks the same bits.
>
> That would be this. If a compiler is reading here and knows how to
> improve the following, please let me know :)
>
> diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
> index 46cc07b5cae6..1f36a4eccc72 100644
> --- a/arch/arm/include/asm/thread_info.h
> +++ b/arch/arm/include/asm/thread_info.h
> @@ -143,8 +143,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
> #define TIF_SYSCALL_TRACE 4 /* syscall trace active */
> #define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */
> #define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */
> -#define TIF_SECCOMP 7 /* seccomp syscall filtering active */
> -#define TIF_NEED_RESCHED_LAZY 8
> +#define TIF_SECCOMP 8 /* seccomp syscall filtering active */
> +#define TIF_NEED_RESCHED_LAZY 7
>
> #define TIF_NOHZ 12 /* in adaptive nohz mode */
> #define TIF_USING_IWMMXT 17
> @@ -170,7 +170,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
> * Change these and you break ASM code in entry-common.S
> */
> #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
> - _TIF_NOTIFY_RESUME | _TIF_UPROBE)
> + _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
> + _TIF_NEED_RESCHED_LAZY)
>
> #endif /* __KERNEL__ */
> #endif /* __ASM_ARM_THREAD_INFO_H */
> diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
> index 30a7228eaceb..c3bd6cbfce4b 100644
> --- a/arch/arm/kernel/entry-common.S
> +++ b/arch/arm/kernel/entry-common.S
> @@ -36,7 +36,9 @@
> UNWIND(.cantunwind )
> disable_irq_notrace @ disable interrupts
> ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
> - tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
> + tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
> + bne fast_work_pending
^^^^^^^^^^^^^^^^
> + tst r1, #_TIF_SECCOMP
> bne fast_work_pending
^^^^^^^^^^^^^^^^^
Should it be "fast_work_pending" in both cases?
>
> /* perform architecture specific actions before user return */
> @@ -62,8 +64,11 @@ ENDPROC(ret_fast_syscall)
> str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
> disable_irq_notrace @ disable interrupts
> ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
> - tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
> + tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
> + bne do_slower_path
> + tst r1, #_TIF_SECCOMP
> beq no_work_pending
> +do_slower_path:
> UNWIND(.fnend )
> ENDPROC(ret_fast_syscall)
>
[...]
--
regards,
-grygorii
next prev parent reply other threads:[~2016-01-25 17:14 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-18 9:08 [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Mike Galbraith
2016-01-18 20:18 ` Sebastian Andrzej Siewior
2016-01-19 2:29 ` Mike Galbraith
2016-01-21 12:54 ` Sebastian Andrzej Siewior
2016-01-22 12:24 ` Grygorii Strashko
2016-01-22 13:19 ` Sebastian Andrzej Siewior
2016-01-22 13:34 ` Grygorii Strashko
2016-01-22 14:14 ` Sebastian Andrzej Siewior
2016-01-22 15:04 ` Grygorii Strashko
2016-01-22 18:21 ` Grygorii Strashko
2016-02-21 15:11 ` [patch] sched,rt: __always_inline preemptible_lazy() Mike Galbraith
2016-01-19 4:41 ` [rfc patch v4.4-rt2] sched: fix up preempt lazy forward port Mike Galbraith
2016-01-19 5:14 ` Mike Galbraith
2016-01-22 11:58 ` Grygorii Strashko
2016-01-22 12:54 ` Sebastian Andrzej Siewior
2016-01-22 20:40 ` Sebastian Andrzej Siewior
2016-01-25 17:14 ` Grygorii Strashko [this message]
2016-02-01 13:04 ` Sebastian Andrzej Siewior
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=56A657DD.8080602@ti.com \
--to=grygorii.strashko@ti.com \
--cc=bigeasy@linutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=umgwanakikbuti@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).