Sorry , missed the forum.
On 12/27/07, arshad hussain <[EMAIL PROTECTED]> wrote:
>
>
>
> On 12/27/07, Wang Yu <[EMAIL PROTECTED]> wrote:
> >
> > My questions are:
> > 1.Why the performances under different subdirs varies so much? for example
> > in /mnt/test/0 the performance is 72/80, while in /mnt/test/1 the
> > performance is 49/53
> >
> >
> My guess is this is not consistent. Over several calls, this is bound to
> vary. As the kernel caches the directory.
>
> 2.The extents of all files are nearly the same, but their performances are
> different. Are there other factors that influence the performance beside of
> the extents(fragmentation) of the file?
> >
> >
> Kernel can bunch various call to block device, together for performance.
> It always caches recently accessed data. (Slab allocator)
>
> 3.Is it true that more files exist in a directory, lower performance? for
> example the performance in /mnt/test/5/tmpfile is 66/75, while the
> performances in /mnt/test/5/tmpfile2 and tmpfile3 are 57/64 and 54/59
> >
> >
> I think you are correct, as the directory grows large enough to jump a
> group
> the performance is bound to suffer.
>
> Thanks
> >
> > --
> > National Research Center for Intelligent Computing Systems
> > Institute of Computing Technology, Chinese Academy of Sciences
>
>
>
