From: Michael Ellerman <mpe@ellerman.id.au>
To: Wang Qing <wangqing@vivo.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Nicholas Piggin <npiggin@gmail.com>,
Jordan Niethe <jniethe5@gmail.com>,
Alistair Popple <alistair@popple.id.au>,
Wang Qing <wangqing@vivo.com>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3] sched/rt, powerpc: Prepare for PREEMPT_RT
Date: Mon, 16 Nov 2020 23:46:51 +1100 [thread overview]
Message-ID: <871rgt4gg4.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <1604998411-16116-1-git-send-email-wangqing@vivo.com>
Wang Qing <wangqing@vivo.com> writes:
> PREEMPT_RT is a separate preemption model, CONFIG_PREEMPT will
> be disabled when CONFIG_PREEMPT_RT is enabled, so we need
> to add CONFIG_PREEMPT_RT output to __die().
>
> Signed-off-by: Wang Qing <wangqing@vivo.com>
Something fairly similar was posted previously.
That time I said:
I don't think there's any point adding the "_RT" to the __die() output
until/if we ever start supporting PREEMPT_RT.
https://lore.kernel.org/linuxppc-dev/87d0ext4q3.fsf@mpe.ellerman.id.au/
And I think I still feel the same way. It's not clear powerpc will ever
support PREEMPT_RT, so this would just be confusing to people. And
potentially someone will then send a patch to remove it as dead code.
cheers
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index 5006dcb..dec7b81
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -262,10 +262,11 @@ static int __die(const char *str, struct pt_regs *regs, long err)
> {
> printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
>
> - printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n",
> + printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s%s %s\n",
> IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
> PAGE_SIZE / 1024, get_mmu_str(),
> IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
> + IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : "",
> IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
> IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
> debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
> --
> 2.7.4
prev parent reply other threads:[~2020-11-16 12:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 8:53 [PATCH V3] sched/rt, powerpc: Prepare for PREEMPT_RT Wang Qing
2020-11-10 10:57 ` Christophe Leroy
2020-11-16 12:46 ` Michael Ellerman [this message]
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