RE: doubt about 99% of the cases if the first byte of the file is cached.

On Tue, 23 Apr 2002, Liang Yang wrote:

> But even we didn't enable noatime, LED should flash only for 1/10 second
> or shorter time since Linux just need to update the access time flag of
> this file. it is not a big job and it shouldn't take Linux a long time
> to update this filed. But we noticed the Hard Disk LED flash for almost
> 2 seconds each time. So maybe Linux is doing some large amount hard disk
> read/write operation instead of just updating file access time flag.

well, is RAM large enough for all files accessed to be cached in RAM?

> I guess for all the sizes of files, the access time flag should be the
> same. Is that correct?

yes, but each file has a different access flag, in different on-disk
positions. So if you are accessing 100 files, the atime update sequence
might create a longer LED flashing.

	Ingo