Re: [PATCH v1 0/4] Kill the time spent in patch_instruction()

[Christophe Leroy]

Le 17/05/2022 à 14:37, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@xxxxxxxxxx> 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.

Christophe