Re: [patch V2 m@/6] perf/core: Split out mlock limit handling

From: Thomas Gleixner
Date: Mon Aug 11 2025 - 08:43:14 EST


On Mon, Aug 11 2025 at 12:49, Peter Zijlstra wrote:
> On Mon, Aug 11, 2025 at 09:06:37AM +0200, Thomas Gleixner wrote:
>> To prepare for splitting the buffer allocation out into seperate functions
>> for the ring buffer and the AUX buffer, split out mlock limit handling into
>> a helper function, which can be called from both.
>>
>> No functional change intended.
>>
>> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
>>
>> ---
>
> Does this not also need this? I found this stray user_extra when I
> eventually removed the local user_extra variable.
>
>
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6997,8 +6997,6 @@ static int perf_mmap(struct file *file,
> if (vma_size != PAGE_SIZE * nr_pages)
> return -EINVAL;
>
> - user_extra = nr_pages;
> -
> mutex_lock(&event->mmap_mutex);
> ret = -EINVAL;
>

No. That's how user_extra is initialized in the first place.

To remove that nr_pages must become an argument to that function.