CVS commit: src/sys/external/bsd/drm2/dist/drm/nouveau/nvkm/subdev/mmu

["matthew green" <mrg%netbsd.org@localhost>]

Module Name:    src
Committed By:   mrg
Date:           Tue May 31 20:53:35 UTC 2022

Modified Files:
        src/sys/external/bsd/drm2/dist/drm/nouveau/nvkm/subdev/mmu:
            nouveau_nvkm_subdev_mmu_mem.c

Log Message:
reorganise most of the NetBSD portion of nvkm_mem_dtor().

when nvkm_mem_new_host() is called via the in-kernel ioctl method,
we copy the supplied dmamap, use it's dm_nsegs value for allocation
of "mem->dma", and assume it remains valid until we're done.

when this path is taken "mem->mem" remains NULL so all the code in
nvkm_mem_dtor() is ignored, and the "mem->dma" is leaked.  this is
one leak seen in PR#56826.  as "dmamap->dm_nsegs" can become invalid
before the dtor call, store the value in "mem->nseg" for use in the
dtor, and convert the dtor to free "mem->dma" if "mem->dma" is set.
additionally, "mem->pages" should end up being the same value as
"nseg" here, ASSERT() this.

while here properly mark NetBSD specific code in nvkm_mem_new_host().

additionally, destroy the dmamap created in the non-ioctl path of
nvkm_mem_new_host().  this is another leak seen in PR#56826.

with both of these fixes my "kmem-04096" pool does not grow rapidly
while using "mpv -vo gpu".  infact, once i loaded the relevant file
into memory, this pool remains stable after at least one minute of
video playback.

ok riastradh@


To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 \
    src/sys/external/bsd/drm2/dist/drm/nouveau/nvkm/subdev/mmu/nouveau_nvkm_subdev_mmu_mem.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.