Messages in this thread | | | Date | Mon, 19 Aug 2013 09:55:03 -0700 | From | Dave Hansen <> | Subject | Re: [PATCH 2/2] mm: add overcommit_kbytes sysctl variable |
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On 08/19/2013 08:17 AM, Jerome Marchand wrote: > Some applications that run on HPC clusters are designed around the > availability of RAM and the overcommit ratio is fine tuned to get the > maximum usage of memory without swapping. With growing memory, the > 1%-of-all-RAM grain provided by overcommit_ratio has become too coarse > for these workload (on a 2TB machine it represents no less than > 20GB). > > This patch adds the new overcommit_kbytes sysctl variable that allow a > much finer grain.
Instead of introducing yet another tunable, why don't we just make the ratio that comes in from the user more fine-grained?
sysctl overcommit_ratio=0.2
We change the internal 'sysctl_overcommit_ratio' to store tenths or hundreths of a percent (or whatever), then parse the input as two integers. I don't think we need fully correct floating point parsing and rounding here, so it shouldn't be too much of a chore. It'd probably end up being less code than you have as it stands.
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