Messages in this thread | | | Subject | Re: File System Performance | From | Steve Lord <> | Date | 12 Nov 2001 15:45:02 -0600 |
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On Mon, 2001-11-12 at 15:43, Andrew Morton wrote:
> > It's tar. It cheats. It somehow detects that the > output is /dev/null, and so it doesn't read the input files. > I think. >
Yep it cheats all right:
execve("/bin/tar", ["tar", "cf", "/dev/null", "linux"], [/* 30 vars */]) = 0 % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 59.70 1.114097 740 1505 getdents64 37.22 0.694516 55 12650 lstat64 1.62 0.030264 39 775 3 open 0.56 0.010518 14 777 close 0.40 0.007395 10 770 fstat64 0.24 0.004553 6 749 fcntl64 0.11 0.001972 986 2 poll 0.02 0.000420 210 2 2 connect 0.02 0.000418 32 13 read 0.02 0.000345 20 17 old_mmap 0.02 0.000286 36 8 munmap 0.02 0.000281 18 16 mmap2 0.01 0.000189 47 4 socket 0.01 0.000161 16 10 brk 0.01 0.000101 51 2 sendto 0.00 0.000076 15 5 mprotect 0.00 0.000076 38 2 recvfrom 0.00 0.000075 25 3 uname 0.00 0.000059 30 2 readv 0.00 0.000057 29 2 bind 0.00 0.000056 28 2 setsockopt 0.00 0.000039 39 1 readlink 0.00 0.000025 13 2 getpid 0.00 0.000023 23 1 rt_sigaction 0.00 0.000021 21 1 time 0.00 0.000021 21 1 gettimeofday 0.00 0.000014 7 2 ioctl ------ ----------- ----------- --------- --------- ---------------- 100.00 1.866058 17324 5 total
Not a lot of reads in there.... I should have known it could not go that fast.
Steve
--
Steve Lord voice: +1-651-683-3511 Principal Engineer, Filesystem Software email: lord@sgi.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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