From: Peter Zijlstra <peterz@infradead.org>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] sched: make struct task_struct::state 32-bit
Date: Mon, 8 Feb 2021 11:39:25 +0100 [thread overview]
Message-ID: <YCEU3SSoYneIh5t1@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210206151832.GA487103@localhost.localdomain>
On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> 32-bit accesses are shorter than 64-bit accesses on x86_64.
> Nothing uses 64-bitness of struct task_struct::state.
>
> Propagate 32-bitness to other variables and functions.
You're saving a handful of bytes, why?
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -655,7 +655,7 @@ struct task_struct {
> struct thread_info thread_info;
> #endif
> /* -1 unrunnable, 0 runnable, >0 stopped: */
> - volatile long state;
> + volatile int state;
A much larger, but probably more useful cleanup would be to get rid of
that volatile.
next prev parent reply other threads:[~2021-02-08 10:51 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-06 15:18 [PATCH 1/5] sched: make struct task_struct::state 32-bit Alexey Dobriyan
2021-02-06 15:20 ` [PATCH 2/5] sched: make nr_running() return 32-bit Alexey Dobriyan
2021-02-06 15:22 ` [PATCH 3/5] sched: make nr_iowait() return 32-bit value Alexey Dobriyan
2021-02-06 15:24 ` [PATCH 4/5] sched: make nr_iowait_cpu() return 32-bit Alexey Dobriyan
2021-02-06 15:30 ` [PATCH 5/5] sched: make multiple runqueue task counters 32-bit Alexey Dobriyan
2021-02-08 10:34 ` [PATCH 1/5] sched: make struct task_struct::state 32-bit Peter Zijlstra
2021-02-08 14:30 ` Alexey Dobriyan
2021-02-08 14:52 ` Alexey Dobriyan
2021-02-08 15:25 ` Peter Zijlstra
2021-02-08 16:45 ` Alexey Dobriyan
2021-02-08 10:39 ` Peter Zijlstra [this message]
2021-02-08 14:33 ` Alexey Dobriyan
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