Re: [PATCH 0/2] userfaultfd: handle few NULL check inline

[Jinjie Ruan <ruanjinjie@huawei.com>]

On 2024/12/9 21:42, Lorenzo Stoakes wrote:
> On Mon, Dec 09, 2024 at 09:25:47PM +0800, Jinjie Ruan wrote:
>> Handle dup_userfaultfd() and anon_vma_fork() NULL check inline to
>> save some function call overhead. The Unixbench single core process
>> create has 1% improve with these patches.
>>
>> Jinjie Ruan (2):
>>   userfaultfd: handle dup_userfaultfd() NULL check inline
>>   mm, rmap: handle anon_vma_fork() NULL check inline
>>
>>  fs/userfaultfd.c              |  5 +----
>>  include/linux/rmap.h          | 12 +++++++++++-
>>  include/linux/userfaultfd_k.h | 11 ++++++++++-
>>  mm/rmap.c                     |  6 +-----
>>  4 files changed, 23 insertions(+), 11 deletions(-)
>>
>> --
>> 2.34.1
>>
> 
> Coincidentally I've just diagosed a rather nasty bug in this code [0], so
> could we hold off on this change for just a little bit until we can get a
> fix out for this please?
> 
> I'd rather not complicate anything until we're sure we won't need to change
> this.

Sure, fix the bugs is a more urgent problem.

Thanks!

> 
> Thanks!
> 
> 
> [0]:https://lore.kernel.org/linux-mm/aa2c1930-becc-4bc5-adfb-96e88290acc7@lucifer.local/
>