linux/drivers
Shakeel Butt b603894248 mm: memcg: add swapcache stat for memcg v2
This patch adds swapcache stat for the cgroup v2.  The swapcache
represents the memory that is accounted against both the memory and the
swap limit of the cgroup.  The main motivation behind exposing the
swapcache stat is for enabling users to gracefully migrate from cgroup
v1's memsw counter to cgroup v2's memory and swap counters.

Cgroup v1's memsw limit allows users to limit the memory+swap usage of a
workload but without control on the exact proportion of memory and swap.
Cgroup v2 provides separate limits for memory and swap which enables more
control on the exact usage of memory and swap individually for the
workload.

With some little subtleties, the v1's memsw limit can be switched with the
sum of the v2's memory and swap limits.  However the alternative for memsw
usage is not yet available in cgroup v2.  Exposing per-cgroup swapcache
stat enables that alternative.  Adding the memory usage and swap usage and
subtracting the swapcache will approximate the memsw usage.  This will
help in the transparent migration of the workloads depending on memsw
usage and limit to v2' memory and swap counters.

The reasons these applications are still interested in this approximate
memsw usage are: (1) these applications are not really interested in two
separate memory and swap usage metrics.  A single usage metric is more
simple to use and reason about for them.

(2) The memsw usage metric hides the underlying system's swap setup from
the applications.  Applications with multiple instances running in a
datacenter with heterogeneous systems (some have swap and some don't) will
keep seeing a consistent view of their usage.

[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]

Link: https://lkml.kernel.org/r/20210108155813.2914586-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
..
accessibility
acpi More ACPI updates for 5.12-rc1 2021-02-23 15:03:05 -08:00
amba
android
ata
atm atm: idt77252: fix build broken on amd64 2021-02-15 12:36:27 -08:00
auxdisplay
base mm: memcg: add swapcache stat for memcg v2 2021-02-24 13:38:29 -08:00
bcma
block xen: branch for v5.12-rc1 2021-02-21 13:06:08 -08:00
bluetooth TTY/Serial driver changes for 5.12-rc1 2021-02-20 21:28:04 -08:00
bus ARM: SoC drivers for v5.12 2021-02-20 18:42:28 -08:00
cdrom
char Pull request for IPMI for 5.12 2021-02-22 18:35:18 -08:00
clk This is all driver updates, the majority of which is a bunch of new Qualcomm 2021-02-22 09:45:23 -08:00
clocksource A small set of clockevent fixes which fell through the cracks 2021-02-22 14:11:36 -08:00
connector
counter
cpufreq Merge branches 'pm-cpufreq' and 'pm-opp' 2021-02-23 19:47:03 +01:00
cpuidle
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-02-21 17:23:56 -08:00
dax
dca
devfreq Merge branches 'pm-devfreq' and 'pm-tools' 2021-02-15 17:02:04 +01:00
dio
dma dmaengine updates for v5.12-rc1 2021-02-23 15:05:10 -08:00
dma-buf dma-buf: Avoid comma separated statements 2021-02-09 17:14:11 +01:00
edac Merge branch 'edac-misc' into edac-updates-for-v5.12 2021-02-15 10:06:58 +01:00
eisa
extcon
firewire
firmware clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
fpga
fsi
gnss
gpio gpio updates for v5.12 2021-02-22 10:00:46 -08:00
gpu Modules updates for v5.12 2021-02-23 10:15:33 -08:00
greybus
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid 2021-02-23 14:52:22 -08:00
hsi
hv Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer" 2021-02-15 10:49:11 +00:00
hwmon Devicetree updates for v5.12: 2021-02-22 10:05:12 -08:00
hwspinlock
hwtracing ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
i2c ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
i3c I3C for 5.12 2021-02-22 09:52:55 -08:00
ide
idle
iio - Use the newly introduced 'hot' and 'critical' ops for the acpi 2021-02-22 09:39:11 -08:00
infiniband Linux 5.11 2021-02-18 11:19:29 -04:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2021-02-23 14:56:23 -08:00
interconnect
iommu IOMMU Updates for Linux v5.12 2021-02-22 10:31:29 -08:00
ipack
irqchip irqchip updates for Linux 5.12: 2021-02-15 15:41:56 +01:00
isdn
leds TTY/Serial driver changes for 5.12-rc1 2021-02-20 21:28:04 -08:00
lightnvm lightnvm: pblk: Replace guid_copy() with export_guid()/import_guid() 2021-02-14 21:27:24 -07:00
macintosh
mailbox
mcb
md - Fix DM integrity's HMAC support to provide enhanced security of 2021-02-22 10:22:54 -08:00
media Fixes around VM_FPNMAP and follow_pfn 2021-02-22 17:45:02 -08:00
memory ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
memstick
message
mfd - Core Frameworks 2021-02-22 09:29:42 -08:00
misc clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
mmc ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
most
mtd This pull request contains changes (actually just fixes) for UBIFS 2021-02-21 13:57:08 -08:00
mux
net RDMA 5.12 merge window pull request 2021-02-22 10:27:48 -08:00
nfc nfc: st-nci: Remove unnecessary variable 2021-02-08 14:56:20 -08:00
ntb
nubus
nvdimm for-5.12/block-2021-02-17 2021-02-21 11:02:48 -08:00
nvme for-5.12/drivers-2021-02-17 2021-02-21 11:06:54 -08:00
nvmem
of Devicetree updates for v5.12: 2021-02-22 10:05:12 -08:00
opp opp: Don't skip freq update for different frequency 2021-02-18 12:31:08 +05:30
parisc
parport
pci Fixes around VM_FPNMAP and follow_pfn 2021-02-22 17:45:02 -08:00
pcmcia
perf IOMMU Updates for Linux v5.12 2021-02-22 10:31:29 -08:00
phy
pinctrl This is the bulk of pin control changes for the v5.12 kernel. 2021-02-22 18:39:11 -08:00
platform - Use the newly introduced 'hot' and 'critical' ops for the acpi 2021-02-22 09:39:11 -08:00
pnp
power
powercap powercap: intel_rapl: Use topology interface in rapl_init_domains() 2021-02-12 16:53:01 +01:00
pps
ps3
ptp ptp: ptp_clockmatrix: clean-up - parenthesis around a == b are unnecessary 2021-02-17 13:49:26 -08:00
pwm
rapidio
ras
regulator - Core Frameworks 2021-02-22 09:29:42 -08:00
remoteproc
reset ARM: SoC drivers for v5.12 2021-02-20 18:42:28 -08:00
rpmsg
rtc ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
s390 SCSI misc on 20210219 2021-02-22 10:24:58 -08:00
sbus
scsi SCSI misc on 20210219 2021-02-22 10:24:58 -08:00
sfi
sh
siox
slimbus
soc This is all driver updates, the majority of which is a bunch of new Qualcomm 2021-02-22 09:45:23 -08:00
soundwire
spi powerpc updates for 5.12 2021-02-22 14:34:00 -08:00
spmi
ssb
staging media updates for v5.12-rc1 2021-02-21 14:10:36 -08:00
target SCSI misc on 20210219 2021-02-22 10:24:58 -08:00
tc
tee Simplify i2c acess in OP-TEE driver 2021-02-09 16:10:49 +01:00
thermal - Use the newly introduced 'hot' and 'critical' ops for the acpi 2021-02-22 09:39:11 -08:00
thunderbolt thunderbolt: Changes for v5.12 merge window 2021-02-09 13:00:07 +01:00
tty ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
uio
usb ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
vdpa
vfio
vhost
video ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
virt
virtio
visorbus
vlynq
vme
w1
watchdog ARM updates for 5.12-rc1: 2021-02-22 14:27:07 -08:00
xen xen: branch for v5.12-rc1 2021-02-21 13:06:08 -08:00
zorro
Kconfig
Makefile