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

[Lorenzo Stoakes]

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.

Thanks!


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