Star64_linux/include
Huang Ying 20b51af15e mm/migrate: add sysfs interface to enable reclaim migration
Some method is obviously needed to enable reclaim-based migration.

Just like traditional autonuma, there will be some workloads that will
benefit like workloads with more "static" configurations where hot pages
stay hot and cold pages stay cold.  If pages come and go from the hot and
cold sets, the benefits of this approach will be more limited.

The benefits are truly workload-based and *not* hardware-based.  We do not
believe that there is a viable threshold where certain hardware
configurations should have this mechanism enabled while others do not.

To be conservative, earlier work defaulted to disable reclaim- based
migration and did not include a mechanism to enable it.  This proposes add
a new sysfs file

  /sys/kernel/mm/numa/demotion_enabled

as a method to enable it.

We are open to any alternative that allows end users to enable this
mechanism or disable it if workload harm is detected (just like
traditional autonuma).

Once this is enabled page demotion may move data to a NUMA node that does
not fall into the cpuset of the allocating process.  This could be
construed to violate the guarantees of cpusets.  However, since this is an
opt-in mechanism, the assumption is that anyone enabling it is content to
relax the guarantees.

Link: https://lkml.kernel.org/r/20210721063926.3024591-9-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-10-ying.huang@intel.com
Signed-off-by: Huang Ying <ying.huang@intel.com>
Originally-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:16 -07:00
..
acpi ACPI: fix NULL pointer dereference 2021-07-24 15:25:54 -07:00
asm-generic vmlinux.lds.h: Handle clang's module.{c,d}tor sections 2021-08-11 12:19:58 -07:00
clocksource
crypto
drm drm: Return -ENOTTY for non-drm ioctls 2021-07-20 15:57:43 +02:00
dt-bindings dt-bindings: clock: r9a07g044-cpg: Update clock/reset definitions 2021-07-12 10:52:03 +02:00
keys
kunit linux-kselftest-kunit-fixes-5.14-rc1 2021-07-02 12:58:26 -07:00
kvm
linux mm/migrate: add sysfs interface to enable reclaim migration 2021-09-03 09:58:16 -07:00
math-emu math-emu: Fix fall-through warning 2021-07-13 13:57:44 -05:00
media
memory
misc
net ipv6: correct comments about fib6_node sernum 2021-08-24 09:59:01 +01:00
pcmcia
ras
rdma
scsi SCSI misc on 20210702 2021-07-02 15:14:36 -07:00
soc Memory controller drivers for v5.14 - Tegra SoC, late fixes 2021-07-16 22:51:01 +02:00
sound ASoC: Fixes for v5.14 2021-07-21 19:48:09 +02:00
target
trace mm/migrate: demote pages during reclaim 2021-09-03 09:58:16 -07:00
uapi Revert "media: dvb header files: move some headers to staging" 2021-08-23 09:49:09 -07:00
vdso
video
xen xen: sync include/xen/interface/io/ring.h with Xen's newest version 2021-07-05 09:49:45 +02:00