Re: Why a find causes a flush?

Richard B. Johnson (root@chaos.analogic.com)
Sun, 9 Aug 1998 21:31:20 -0400 (EDT)


On 9 Aug 1998 peloy@ven.ra.rockwell.com wrote:

> Hi,
>
> I wonder why doing a "find /some_dir" causes the kernel to mark buffers
> as dirty so the next scheduled flush writes these buffers out to disk.
>
> I haven't taken any look at the code but I see how the dcache saves
> accesses to disk when doing the find, but I can also see how the disk
> is accessed about 2 seconds after find finishes, or when sync is run.
>
> This is with kernel 2.1.115 and there's nothing bad, it is just that I
> am curious why this behavior...
>
> peloy.-

You just accessed a bunch of directory files. The access time will
get updated because it changed. There are presently 3 times in
the ext2 file-system, st_atime, st_mtime, and st_ctime. I have
heard, but not tried, that you can mount file-systems with a
"noatime" feature, defined in ..../linux/fs.h. You need a
recent version of `mount` to use this feature.

Cheers,
Dick Johnson
***** FILE SYSTEM WAS MODIFIED *****
Penguin : Linux version 2.1.113 on an i586 machine (66.15 BogoMips).
Warning : It's hard to remain at the trailing edge of technology.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html