On 19.10.22 00:54, Andrew Morton wrote:
On Tue, 18 Oct 2022 09:00:22 +0000 xu xin <xu.xin.sc@xxxxxxxxx> wrote:
A full description of the real-world end-user operational benefits of
these changes would help, please.
The core idea of this patch set is to enable users to perceive the number of any
pages merged by KSM, regardless of whether use_zero_page switch has been turned
on, so that users can know how much free memory increase is really due to their
madvise(MERGEABLE) actions.
OK, thanks.
The motivation for me to do this is that when I do
an application optimization of KSM on embedded Linux for 5G platform, I find
that ksm_merging_pages of some process becomes very small(but used to be large),
which led me to think that there was any problem with the application KSM-madvise
strategy, but in fact, it was only because use_zero_pages is on.
Please expand on the above motivation and experience, and include it in
the [0/n] changelog. But let's leave it a few days to see if there's
additional reviewer input.
I just posted a selftest:
https://lore.kernel.org/all/20221021101141.84170-5-david@xxxxxxxxxx/T/#u
That could (should) be extended to test if unmerging works as expected.
Having that said, I think we really want a second pair of (KSM-expert)
eyes on these changes before moving forward with them.
--
Thanks,
David / dhildenb
