On Tue, 3 Jun 2025 at 10:26, Steven Rostedt <rost...@goodmis.org> wrote:
>
> config DRM_TTM
> tristate
> - depends on DRM && MMU
> + depends on DRM && MMU && SHMEM
Yeah, except I think you should just make it be
depends on DRM && SHMEM
because SHMEM already depends on MMU.
That said, our docs already say that if you disable SHMEM, it gets
replaced by RAMFS, so maybe just having a ramfs version is the
RightThing(tm).
I don't think such a ramfs version should just return 0 - much less an
error. I think it should always redirty the page.
IOW, I think the "ramfs" version should look something like
folio_mark_dirty(folio);
if (wbc->for_reclaim)
return AOP_WRITEPAGE_ACTIVATE; /* Return with folio locked */
folio_unlock(folio);
return 0;
which is what shmem does for the "page is locked" case.
Linus
