From: Pan Xinhui <xinhui@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
"Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>,
Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Cc: benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com
Subject: Re: [PATCH] powerpc/xmon: Fix an unexpected xmon onoff state change
Date: Fri, 17 Feb 2017 17:30:23 +0800 [thread overview]
Message-ID: <cecc8a28-4e2f-8e03-0b1a-8a9ac60c0c71@linux.vnet.ibm.com> (raw)
In-Reply-To: <87h93tjqrn.fsf@concordia.ellerman.id.au>
在 2017/2/17 14:05, Michael Ellerman 写道:
> Pan Xinhui <xinhui@linux.vnet.ibm.com> writes:
>> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
>> index 9c0e17c..f6e5c3d 100644
>> --- a/arch/powerpc/xmon/xmon.c
>> +++ b/arch/powerpc/xmon/xmon.c
>> @@ -76,6 +76,7 @@ static int xmon_gate;
>> #endif /* CONFIG_SMP */
>>
>> static unsigned long in_xmon __read_mostly = 0;
>> +static int xmon_off = !IS_ENABLED(CONFIG_XMON_DEFAULT);
>
> I think the logic would probably clearer if we invert this to become
> xmon_on.
>
yep, make sense.
>> @@ -3266,16 +3269,16 @@ static int __init setup_xmon_sysrq(void)
>> __initcall(setup_xmon_sysrq);
>> #endif /* CONFIG_MAGIC_SYSRQ */
>>
>> -static int __initdata xmon_early, xmon_off;
>> +static int __initdata xmon_early;
>>
>> static int __init early_parse_xmon(char *p)
>> {
>> if (!p || strncmp(p, "early", 5) == 0) {
>> /* just "xmon" is equivalent to "xmon=early" */
>> - xmon_init(1);
>> xmon_early = 1;
>> + xmon_off = 0;
>> } else if (strncmp(p, "on", 2) == 0)
>> - xmon_init(1);
>> + xmon_off = 0;
>
> You've just changed the timing of when xmon gets enabled for the above
> two cases, from here which is called very early, to xmon_setup() which
> is called much later in boot.
>
> That effectively disables xmon for most of the boot, which we do not
> want to do.
>
Although it is not often that kernel got stucked during boot. Yes, the behavior changed anyway. Will fix that in v3.
> cheers
>
next prev parent reply other threads:[~2017-02-17 9:41 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-15 7:49 [PATCH] powerpc/xmon: Fix an unexpected xmon onoff state change Pan Xinhui
2017-02-15 21:22 ` Guilherme G. Piccoli
2017-02-16 5:09 ` Michael Ellerman
2017-02-16 10:57 ` Guilherme G. Piccoli
2017-02-16 11:51 ` Pan Xinhui
2017-02-17 6:05 ` Michael Ellerman
2017-02-17 9:30 ` Pan Xinhui [this message]
2017-02-17 12:25 ` Guilherme G. Piccoli
2017-02-20 4:46 ` Michael Ellerman
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