Re: [PATCH 1/1] mm: change inlined allocation helpers to account at the call site

Matthew Wilcox
2024-04-04T22:33:39Z

On Thu, Apr 04, 2024 at 03:17:43PM -0700, Suren Baghdasaryan wrote:
> Ironically, checkpatch generates warnings for these type casts:
>
> WARNING: unnecessary cast may hide bugs, see
> http://c-faq.com/malloc/mallocnocast.html
> #425: FILE: include/linux/dma-fence-chain.h:90:
> + ((struct dma_fence_chain *)kmalloc(sizeof(struct dma_fence_chain),
> GFP_KERNEL))
>
> I guess I can safely ignore them in this case (since we cast to the
> expected type)?

I find ignoring checkpatch to be a solid move 99% of the time.

I really don't like the codetags. This is so much churn, and it could
all be avoided by just passing in _RET_IP_ or _THIS_IP_ depending on
whether we wanted to profile this function or its caller. vmalloc
has done it this way since 2008 (OK, using __builtin_return_address())
and lockdep has used _THIS_IP_ / _RET_IP_ since 2006.