lkml.org 
[lkml]   [2023]   [Jan]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] mm,page_alloc,cma: configurable CMA utilization
From
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(-)
>

\
 
 \ /
  Last update: 2023-03-27 00:03    [W:0.061 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site