Am 02.07.24 um 08:40 schrieb Christoph Hellwig:
On Mon, Jul 01, 2024 at 11:26:34PM -0700, Andrew Morton wrote:
No, I do think the cast is useful:
struct page *page = dma_fence_chain_alloc();
will presently generate a warning. We want this. Your change will
remove that useful warning.
Unrelatedly: there is no earthly reason why this is implemented as a
macro. A static inline function would be so much better. Why do we
keep doing this.
Agreed with all of the above. Adding the dmabuf maintainers.
Thanks for adding me and I have to ask to be added on DMA-buf patches
when initially sending them out.
First of all: Yes that cast is intentionally there and yes that is
intentionally a define and not an inline function.
See this patch here which changed that:
commit 2c321f3f70bc284510598f712b702ce8d60c4d14
Author: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Date: Sun Apr 14 19:07:31 2024 -0700
mm: change inlined allocation helpers to account at the call site
Main goal of memory allocation profiling patchset is to provide
accounting
that is cheap enough to run in production. To achieve that we inject
counters using codetags at the allocation call sites to account
every time
allocation is made. This injection allows us to perform accounting
efficiently because injected counters are immediately available as
opposed
to the alternative methods, such as using _RET_IP_, which would require
counter lookup and appropriate locking that makes accounting much more
expensive. This method requires all allocation functions to inject
separate counters at their call sites so that their callers can be
individually accounted. Counter injection is implemented by allocation
hooks which should wrap all allocation functions.
Inlined functions which perform allocations but do not use allocation
hooks are directly charged for the allocations they perform. In most
cases these functions are just specialized allocation wrappers used
from
multiple places to allocate objects of a specific type. It would
be more
useful to do the accounting at their call sites instead. Instrument
these
helpers to do accounting at the call site. Simple inlined allocation
wrappers are converted directly into macros. More complex
allocators or
allocators with documentation are converted into _noprof versions and
allocation hooks are added. This allows memory allocation profiling
mechanism to charge allocations to the callers of these functions.
Regards,
Christian.
