| Message ID | 20220422062436.14384-1-mark-pk.tsai@mediatek.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | dma-mapping, remoteproc: Fix dma_mem leak after rproc_shutdown | expand |
Sigh. In theory drivers should never declare coherent memory like this, and there has been some work to fix remoteproc in that regard. But I guess until that is merged we'll need somthing like this fix.
> Sigh. In theory drivers should never declare coherent memory like > this, and there has been some work to fix remoteproc in that regard. > > But I guess until that is merged we'll need somthing like this fix. Hi, Thanks for your comment. As I didn't see other fix of this issue, should we use this patch before the remoteproc work you mentioned is merged?
On 2022-05-23 11:15, Mark-PK Tsai wrote: >> Sigh. In theory drivers should never declare coherent memory like >> this, and there has been some work to fix remoteproc in that regard. >> >> But I guess until that is merged we'll need somthing like this fix. > > Hi, > > Thanks for your comment. > As I didn't see other fix of this issue, should we use this patch > before the remoteproc work you mentioned is merged? TBH I think it would be better "fixed" with a kmemleak_ignore() and a big comment, rather than adding API cruft for something that isn't a real problem. I'm quite sure that no real-world user is unbinding remoteproc drivers frequently enough that leaking a 48-byte allocation each time has any practical significance. Thanks, Robin.
> >> Sigh. In theory drivers should never declare coherent memory like > >> this, and there has been some work to fix remoteproc in that regard. > >> > >> But I guess until that is merged we'll need somthing like this fix. > > > > Hi, > > > > Thanks for your comment. > > As I didn't see other fix of this issue, should we use this patch > > before the remoteproc work you mentioned is merged? > > TBH I think it would be better "fixed" with a kmemleak_ignore() and a > big comment, rather than adding API cruft for something that isn't a > real problem. I'm quite sure that no real-world user is unbinding > remoteproc drivers frequently enough that leaking a 48-byte allocation > each time has any practical significance. > Actually we stop 2 remote processors using the same remoteproc driver when system suspend or screen off on our arm64 platform. And the 48-byte slab allocation will be aligned up to 128 bytes on arm64. So the leak can be significant in our use case especially in stress test... We really don't want to ignore it. Maybe there're other way to fix it without adding APIs?
On Sat, Apr 23, 2022 at 07:46:50PM +0200, Christoph Hellwig wrote: > Sigh. In theory drivers should never declare coherent memory like > this, and there has been some work to fix remoteproc in that regard. > > But I guess until that is merged we'll need somthing like this fix. Should I take this in the remoteproc tree? If so, can I get an RB? Thanks, Mathieu
On Wed, Jun 22, 2022 at 10:25:40AM -0600, Mathieu Poirier wrote: > On Sat, Apr 23, 2022 at 07:46:50PM +0200, Christoph Hellwig wrote: > > Sigh. In theory drivers should never declare coherent memory like > > this, and there has been some work to fix remoteproc in that regard. > > > > But I guess until that is merged we'll need somthing like this fix. > > Should I take this in the remoteproc tree? If so, can I get an RB? Reluctantly-Acked-by: Christoph Hellwig <hch@lst.de>
On Fri, Apr 22, 2022 at 02:24:34PM +0800, Mark-PK Tsai wrote: > Release dma coherent memory before rvdev is free in > rproc_rvdev_release(). > > Below is the kmemleak report: > unreferenced object 0xffffff8051c1a980 (size 128): > comm "sh", pid 4895, jiffies 4295026604 (age 15481.896s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<000000003a0f3ec0>] dma_declare_coherent_memory+0x44/0x11c > [<00000000ad243164>] rproc_add_virtio_dev+0xb8/0x20c > [<00000000d219c8e9>] rproc_vdev_do_start+0x18/0x24 > [<00000000e694b468>] rproc_start+0x22c/0x3e0 > [<000000000b938941>] rproc_boot+0x4a4/0x860 > [<000000003c4dc532>] state_store.52856+0x10c/0x1b8 > [<00000000df2297ac>] dev_attr_store+0x34/0x84 > [<0000000083a53bdb>] sysfs_kf_write+0x60/0xbc > [<000000008ed830df>] kernfs_fop_write+0x198/0x458 > [<0000000072b9ad06>] __vfs_write+0x50/0x210 > [<00000000377d7469>] vfs_write+0xe4/0x1a8 > [<00000000c3fc594e>] ksys_write+0x78/0x144 > [<000000009aef6f4b>] __arm64_sys_write+0x1c/0x28 > [<0000000003496a98>] el0_svc_common+0xc8/0x22c > [<00000000ea3fe7a3>] el0_svc_compat_handler+0x1c/0x28 > [<00000000d1a85a4e>] el0_svc_compat+0x8/0x24 > > Mark-PK Tsai (2): > dma-mapping: Add dma_release_coherent_memory to DMA API > remoteproc: Fix dma_mem leak after rproc_shutdown > > drivers/remoteproc/remoteproc_core.c | 1 + > include/linux/dma-map-ops.h | 3 +++ > kernel/dma/coherent.c | 10 ++++++++-- > 3 files changed, 12 insertions(+), 2 deletions(-) Applied. Thanks, Mathieu > > -- > 2.18.0 >
Release dma coherent memory before rvdev is free in rproc_rvdev_release(). Below is the kmemleak report: unreferenced object 0xffffff8051c1a980 (size 128): comm "sh", pid 4895, jiffies 4295026604 (age 15481.896s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000003a0f3ec0>] dma_declare_coherent_memory+0x44/0x11c [<00000000ad243164>] rproc_add_virtio_dev+0xb8/0x20c [<00000000d219c8e9>] rproc_vdev_do_start+0x18/0x24 [<00000000e694b468>] rproc_start+0x22c/0x3e0 [<000000000b938941>] rproc_boot+0x4a4/0x860 [<000000003c4dc532>] state_store.52856+0x10c/0x1b8 [<00000000df2297ac>] dev_attr_store+0x34/0x84 [<0000000083a53bdb>] sysfs_kf_write+0x60/0xbc [<000000008ed830df>] kernfs_fop_write+0x198/0x458 [<0000000072b9ad06>] __vfs_write+0x50/0x210 [<00000000377d7469>] vfs_write+0xe4/0x1a8 [<00000000c3fc594e>] ksys_write+0x78/0x144 [<000000009aef6f4b>] __arm64_sys_write+0x1c/0x28 [<0000000003496a98>] el0_svc_common+0xc8/0x22c [<00000000ea3fe7a3>] el0_svc_compat_handler+0x1c/0x28 [<00000000d1a85a4e>] el0_svc_compat+0x8/0x24 Mark-PK Tsai (2): dma-mapping: Add dma_release_coherent_memory to DMA API remoteproc: Fix dma_mem leak after rproc_shutdown drivers/remoteproc/remoteproc_core.c | 1 + include/linux/dma-map-ops.h | 3 +++ kernel/dma/coherent.c | 10 ++++++++-- 3 files changed, 12 insertions(+), 2 deletions(-)