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

From: Michael Ellerman
Date: Tue May 17 2022 - 08:37:50 EST


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.

cheers