Messages in this thread | | | Date | Tue, 31 Jan 2023 16:26:06 +0200 | Subject | Re: [PATCH] mm,page_alloc,cma: configurable CMA utilization | From | Georgi Djakov <> |
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Hi Sukadev,
On 31.01.23 9:10, Sukadev Bhattiprolu wrote: > > Commit 16867664936e ("mm,page_alloc,cma: conditionally prefer cma pageblocks for movable allocations") > added support to use CMA pages when more than 50% of total free pages in > the zone are free CMA pages. > > However, with multiplatform kernels a single binary is used across different > targets of varying memory sizes. A low memory target using one such kernel > would incur allocation failures even when sufficient memory is available in > the CMA region. On these targets we would want to utilize a higher percentage > of the CMA region and reduce the allocation failures, even if it means that a > subsequent cma_alloc() would take longer. > > Make the percentage of CMA utilization a configurable parameter to allow > for such usecases.
The above makes sense to me. But it also needs to documented like the other sysctl files in Documentation/admin-guide/sysctl/vm.rst
Thanks, Georgi
> > Signed-off-by: Sukadev Bhattiprolu <quic_sukadev@quicinc.com> > --- > Note: There was a mention about it being the last resort to making this > percentage configurable (https://lkml.org/lkml/2020/3/12/751). But > as explained above, multi-platform kernels for varying memory size > targets would need this to be configurable. > --- > include/linux/mm.h | 1 + > kernel/sysctl.c | 8 ++++++++ > mm/page_alloc.c | 18 +++++++++++++++--- > mm/util.c | 2 ++ > 4 files changed, 26 insertions(+), 3 deletions(-) >
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