PR/56826 CVS commit: src/sys/external/bsd/drm2/dist/drm/nouveau/nvkm/subdev/mmu

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

The following reply was made to PR kern/56826; it has been noted by GNATS.

From: "matthew green" <mrg%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/56826 CVS commit: src/sys/external/bsd/drm2/dist/drm/nouveau/nvkm/subdev/mmu
Date: Tue, 31 May 2022 20:53:35 +0000

 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.