Date: Mon, 14 May 2012 21:23:11 +0200 From: =?ISO-8859-1?Q?Fredrik_Sik=E9n?= <fredrik.siken@gmail.com> To: freebsd-arm@freebsd.org Subject: 13x longer execution times before remount Message-ID: <CAGh%2B35MFtuDFjMkkHV%2B=X4g4uWmkG0AyJxdutFMwxfve-pUwqg@mail.gmail.com>
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Hi,
I've an 8.2-Release running on an ARM with poor execution performance
before a remount is performed.
The scenario is as follows
0) I mount an UFS SSD disk
# mount -o noclusterr -o noclusterw /dev/ad0s1 /mnt/
1) I copy an executable to an UFS mounted SSD disk and measure its
time of execution from start to stop
2) I remount the system (umount/mount)
3) I perform the same steps as in 1) but now with a performance increase of 13x
Other tests performed:
- Tested on a UFS USB stick with the same behaviour
- Tested to write to an NFS mounted disk and this gives the expected
behaviour - the same time before and after a remount.
- Running the same version on a x86 gives the expected behaviour - the
same time before and after a remount.
Results after file is copied but before a remount
# time ./test 10000 1000000
size = 10000, no = 1000000
133.000u 0.000s 2:13.53 99.8% 3282+18575k 0+0io 0pf+0w
Results after a remount
# time ./test 10000 1000000
size = 10000, no = 1000000
7.000u 0.000s 0:07.82 99.8% 3286+18595k 0+0io 0pf+0w
The test application source looks like this
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
int main(int argc, char **argv) {
int size = atoi(argv[1]);
int no = atoi(argv[2]);
printf("size = %d, no = %d\n", size, no);
{
int i;
for(i = 0 ; i<no ; i++) {
char *p = malloc(size);
memset(p, 0, size);
free(p);
}
}
}
Thanks,
Fredrik
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