Re: [RFC PATCH 00/25] Accelerate page migration and use memcg for PMEM management

[Michal Hocko]

On Wed 03-04-19 19:00:21, Zi Yan wrote:
> From: Zi Yan <ziy@xxxxxxxxxx>
> 
> Thanks to Dave Hansen's patches, which make PMEM as part of memory as NUMA nodes.
> How to use PMEM along with normal DRAM remains an open problem. There are
> several patchsets posted on the mailing list, proposing to use page migration to
> move pages between PMEM and DRAM using Linux page replacement policy [1,2,3].
> There are some important problems not addressed in these patches:
> 1. The page migration in Linux does not provide high enough throughput for us to
> fully exploit PMEM or other use cases.
> 2. Linux page replacement is running too infrequent to distinguish hot and cold
> pages.
[...]
>  33 files changed, 4261 insertions(+), 162 deletions(-)

For a patch _this_ large you should really start with a real world
usecasing hitting bottlenecks with the current implementation. Should
microbenchmarks can trigger bottlenecks much easier but do real
application do the same? Please give us some numbers.
-- 
Michal Hocko
SUSE Labs