| Message ID | 20170228002353.3101-1-shuahkh@osg.samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Shuah, The subject line isn't consistent with what's used for exynos_defconfig changes, please use instead: ARM: exynos_defconfig: Increase CONFIG_CMA_SIZE_MBYTES to 96 On 02/27/2017 09:23 PM, Shuah Khan wrote: > Current CMA size of 64 Mbytes is right on the edge of being too small > for some display managers. With the proposed s5p_mfc patch series that > pre-allocate buffers, when display manager starts, it fails to get GEM > buffers. Increasing the CMA size to 96 solves the problem. > > Change CONFIG_CMA_SIZE_MBYTES to 96 in exynos_defconfig to address the > problem. > As you mention, the problem is when a driver pre-allocates a lot of CMA memory. So instead of mentioning an in-flight patch series, I would make the commit message more generic. Something along the following lines: Current CMA size is 64 Mbytes, but this may not be enough if different drivers need to allocate big memory chunks. For example, the s5p-mfc driver may need to do a pre-allocation of N MiB to decode a H.264 1080p video, and there won't be enough CMA memory left for others drivers, like the exynos-drm driver that may need to allocate GEM buffers for the display manager. Increasing the CMA size to 96 MiB should be enough for most use cases. > Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> > Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- Patch looks good to me though. Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Best regards,
On 02/28/2017 09:42 AM, Javier Martinez Canillas wrote: > Hello Shuah, > > The subject line isn't consistent with what's used for exynos_defconfig > changes, please use instead: > > ARM: exynos_defconfig: Increase CONFIG_CMA_SIZE_MBYTES to 96 > oops - I meant o make it exynos_defconfig > On 02/27/2017 09:23 PM, Shuah Khan wrote: >> Current CMA size of 64 Mbytes is right on the edge of being too small >> for some display managers. With the proposed s5p_mfc patch series that >> pre-allocate buffers, when display manager starts, it fails to get GEM >> buffers. Increasing the CMA size to 96 solves the problem. >> >> Change CONFIG_CMA_SIZE_MBYTES to 96 in exynos_defconfig to address the >> problem. >> > > As you mention, the problem is when a driver pre-allocates a lot of CMA > memory. So instead of mentioning an in-flight patch series, I would make > the commit message more generic. Something along the following lines: I thought about making it generic and decided to mention the problem I am seeing, so there is a context to it. Without this patch, some display managers will see regression. > > Current CMA size is 64 Mbytes, but this may not be enough if different > drivers need to allocate big memory chunks. > > For example, the s5p-mfc driver may need to do a pre-allocation of N MiB > to decode a H.264 1080p video, and there won't be enough CMA memory left > for others drivers, like the exynos-drm driver that may need to allocate > GEM buffers for the display manager. > > Increasing the CMA size to 96 MiB should be enough for most use cases. I will add the current problem to throw away section of the patch for more information. > >> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> >> Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com> >> --- > > Patch looks good to me though. > > Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> thanks for the review. I will send v2 with your reviewed by tag > > Best regards, > -- Shuah
On Tue, Feb 28, 2017 at 09:52:33AM -0700, Shuah Khan wrote: > On 02/28/2017 09:42 AM, Javier Martinez Canillas wrote: > > Hello Shuah, > > > > The subject line isn't consistent with what's used for exynos_defconfig > > changes, please use instead: > > > > ARM: exynos_defconfig: Increase CONFIG_CMA_SIZE_MBYTES to 96 > > > > oops - I meant o make it exynos_defconfig > > > On 02/27/2017 09:23 PM, Shuah Khan wrote: > >> Current CMA size of 64 Mbytes is right on the edge of being too small > >> for some display managers. With the proposed s5p_mfc patch series that > >> pre-allocate buffers, when display manager starts, it fails to get GEM > >> buffers. Increasing the CMA size to 96 solves the problem. > >> > >> Change CONFIG_CMA_SIZE_MBYTES to 96 in exynos_defconfig to address the > >> problem. > >> > > > > As you mention, the problem is when a driver pre-allocates a lot of CMA > > memory. So instead of mentioning an in-flight patch series, I would make > > the commit message more generic. Something along the following lines: > > I thought about making it generic and decided to mention the problem I am > seeing, so there is a context to it. Without this patch, some display > managers will see regression. > > > > > Current CMA size is 64 Mbytes, but this may not be enough if different > > drivers need to allocate big memory chunks. > > > > For example, the s5p-mfc driver may need to do a pre-allocation of N MiB > > to decode a H.264 1080p video, and there won't be enough CMA memory left > > for others drivers, like the exynos-drm driver that may need to allocate > > GEM buffers for the display manager. > > > > Increasing the CMA size to 96 MiB should be enough for most use cases. > > I will add the current problem to throw away section of the patch for more > information. > > > > >> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> > >> Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com> > >> --- > > > > Patch looks good to me though. > > > > Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> > > thanks for the review. I will send v2 with your reviewed by tag While at it, please put Suggested-by before Sob tag (let's say chronological order). Best regards, Krzysztof
diff --git a/arch/arm/configs/exynos_defconfig b/arch/arm/configs/exynos_defconfig index 742baf0..2541414 100644 --- a/arch/arm/configs/exynos_defconfig +++ b/arch/arm/configs/exynos_defconfig @@ -53,7 +53,7 @@ CONFIG_RFKILL_REGULATOR=y CONFIG_DEVTMPFS=y CONFIG_DEVTMPFS_MOUNT=y CONFIG_DMA_CMA=y -CONFIG_CMA_SIZE_MBYTES=64 +CONFIG_CMA_SIZE_MBYTES=96 CONFIG_BLK_DEV_LOOP=y CONFIG_BLK_DEV_CRYPTOLOOP=y CONFIG_BLK_DEV_RAM=y
Current CMA size of 64 Mbytes is right on the edge of being too small for some display managers. With the proposed s5p_mfc patch series that pre-allocate buffers, when display manager starts, it fails to get GEM buffers. Increasing the CMA size to 96 solves the problem. Change CONFIG_CMA_SIZE_MBYTES to 96 in exynos_defconfig to address the problem. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com> --- arch/arm/configs/exynos_defconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)