Re: RFC: Memory Tiering Kernel Interfaces (v2)
From: Aneesh Kumar K V
Date: Wed May 25 2022 - 06:01:54 EST
On 5/25/22 2:33 PM, Ying Huang wrote:
On Tue, 2022-05-24 at 22:32 -0700, Wei Xu wrote:
On Tue, May 24, 2022 at 1:24 AM Ying Huang <ying.huang@xxxxxxxxx> wrote:
On Tue, 2022-05-24 at 00:04 -0700, Wei Xu wrote:
On Thu, May 19, 2022 at 8:06 PM Ying Huang <ying.huang@xxxxxxxxx> wrote:
...
OK. Just to confirm. Does this mean that we will have fixed device ID,
for example,
GPU memtier255
DRAM (with CPU) memtier0
PMEM memtier1
When we add a new memtier, it can be memtier254, or memter2? The rank
value will determine the real demotion order.
I think you may need to send v3 to make sure everyone is at the same
page.
What we have implemented which we will send as RFC shortly is below.
cd /sys/dekvaneesh@ubuntu-guest:~$ cd /sys/devices/system/
kvaneesh@ubuntu-guest:/sys/devices/system$ pwd
/sys/devices/system
kvaneesh@ubuntu-guest:/sys/devices/system$ ls
clockevents clocksource container cpu edac memory memtier mpic
node power
kvaneesh@ubuntu-guest:/sys/devices/system$ cd memtier/
kvaneesh@ubuntu-guest:/sys/devices/system/memtier$ pwd
/sys/devices/system/memtier
kvaneesh@ubuntu-guest:/sys/devices/system/memtier$ ls
default_rank max_rank memtier1 power uevent
kvaneesh@ubuntu-guest:/sys/devices/system/memtier$ cat default_rank
1
kvaneesh@ubuntu-guest:/sys/devices/system/memtier$ cat max_rank
3
kvaneesh@ubuntu-guest:/sys/devices/system/memtier$ cd memtier1/
kvaneesh@ubuntu-guest:/sys/devices/system/memtier/memtier1$ ls
nodelist power rank subsystem uevent
kvaneesh@ubuntu-guest:/sys/devices/system/memtier/memtier1$ cat nodelist
0-3
kvaneesh@ubuntu-guest:/sys/devices/system/memtier/memtier1$ cat rank
1
kvaneesh@ubuntu-guest:/sys/devices/system/memtier/memtier1$ cd
../../node/node1/
kvaneesh@ubuntu-guest:/sys/devices/system/node/node1$ cat memtier
1
kvaneesh@ubuntu-guest:/sys/devices/system/node/node1$
root@ubuntu-guest:/sys/devices/system/node/node1# echo 0 > memtier
root@ubuntu-guest:/sys/devices/system/node/node1# cat memtier
0
root@ubuntu-guest:/sys/devices/system/node/node1# cd ../../memtier/
root@ubuntu-guest:/sys/devices/system/memtier# ls
default_rank max_rank memtier0 memtier1 power uevent
root@ubuntu-guest:/sys/devices/system/memtier# cd memtier0/
root@ubuntu-guest:/sys/devices/system/memtier/memtier0# cat nodelist
1
root@ubuntu-guest:/sys/devices/system/memtier/memtier0# cat rank
0
root@ubuntu-guest:/sys/devices/system/memtier/memtier0# echo 4 > rank
bash: rank: Permission denied
root@ubuntu-guest:/sys/devices/system/memtier/memtier0#