lkml.org 
[lkml]   [2018]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectKSM not working in 4.9 Kernel
Hi All,

Board: Hikey620 ARM64
Kernel: 4.9.20

I am trying to verify KSM (Kernel Same Page Merging) functionality on
4.9 Kernel using "mmap" and madvise user space test utility.
But to my observation, it seems KSM is not working for me.
CONFIG_KSM=y is enabled in kernel.
ksm_init is also called during boot up.
443 ? SN 0:00 [ksmd]

ksmd thread is also running.

However, when I see the sysfs, no values are written.
~ # grep -H '' /sys/kernel/mm/ksm/*
/sys/kernel/mm/ksm/pages_hashed:0
/sys/kernel/mm/ksm/pages_scanned:0
/sys/kernel/mm/ksm/pages_shared:0
/sys/kernel/mm/ksm/pages_sharing:0
/sys/kernel/mm/ksm/pages_to_scan:200
/sys/kernel/mm/ksm/pages_unshared:0
/sys/kernel/mm/ksm/pages_volatile:0
/sys/kernel/mm/ksm/run:1
/sys/kernel/mm/ksm/sleep_millisecs:1000

So, please let me know if I am doing any thing wrong.

This is the test utility:
int main(int argc, char *argv[])
{
int i, n, size;
char *buffer;
void *addr;

n = 100;
size = 100 * getpagesize();
for (i = 0; i < n; i++) {
buffer = (char *)malloc(size);
memset(buffer, 0xff, size);
addr = mmap(NULL, size,
PROT_READ | PROT_EXEC | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS,
-1, 0);
madvise(addr, size, MADV_MERGEABLE);
sleep(1);
}
printf("Done....press ^C\n");

pause();

return 0;
}



Thanks,
Pintu

\
 
 \ /
  Last update: 2018-09-14 16:28    [W:0.268 / U:1.236 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site