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Date:   Fri, 24 Jun 2022 09:06:43 +0200
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Subject: Re: [PATCH v1 0/4] Kill the time spent in patch_instruction()
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From:   Christophe Leroy <christophe.leroy@csgroup.eu>
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Michael Ellerman <patch-notifications@ellerman.id.au>,
        Paul Mackerras <paulus@samba.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc:     "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <cover.1647962456.git.christophe.leroy@csgroup.eu>
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 <b5fb2df0-911b-ee84-9377-fc426c081adc@csgroup.eu>
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Michael ?

Le 31/05/2022 à 08:24, Christophe Leroy a écrit :
> 
> 
> Le 17/05/2022 à 14:37, Michael Ellerman a écrit :
>> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>>> Le 15/05/2022 à 12:28, Michael Ellerman a écrit :
>>>> On Tue, 22 Mar 2022 16:40:17 +0100, Christophe Leroy wrote:
>>>>> This series reduces by 70% the time required to activate
>>>>> ftrace on an 8xx with CONFIG_STRICT_KERNEL_RWX.
>>>>>
>>>>> Measure is performed in function ftrace_replace_code() using mftb()
>>>>> around the loop.
>>>>>
>>>>> With the series,
>>>>> - Without CONFIG_STRICT_KERNEL_RWX, 416000 TB ticks are measured.
>>>>> - With CONFIG_STRICT_KERNEL_RWX, 546000 TB ticks are measured.
>>>>>
>>>>> [...]
>>>>
>>>> Patches 1, 3 and 4 applied to powerpc/next.
>>>>
>>>> [1/4] powerpc/code-patching: Don't call is_vmalloc_or_module_addr() 
>>>> without CONFIG_MODULES
>>>>         
>>>> https://git.kernel.org/powerpc/c/cb3ac45214c03852430979a43180371a44b74596 
>>>>
>>>> [3/4] powerpc/code-patching: Use jump_label for testing freed initmem
>>>>         
>>>> https://git.kernel.org/powerpc/c/b033767848c4115e486b1a51946de3bee2ac0fa6 
>>>>
>>>> [4/4] powerpc/code-patching: Use jump_label to check if 
>>>> poking_init() is done
>>>>         
>>>> https://git.kernel.org/powerpc/c/1751289268ef959db68b0b6f798d904d6403309a 
>>>>
>>>>
>>>
>>> Patch 2 was the keystone of this series. What happened to it ?
>>
>> It broke on 64-bit. I think I know why but I haven't had time to test
>> it. Will try and get it fixed in the next day or two.
>>
> 
> You didn't find any solution at the end, or didn't have time ?
> 
> What was the problem exactly ? I made a quick try on QEMU and it was 
> working as expected.
> 

Should I make it a ppc32-only change ?