Sorry , missed the forum.
On 12/27/07, arshad hussain <arshad.super@xxxxxxxxx> wrote:
On 12/27/07, Wang Yu <wangyuict@xxxxxxxxx > 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
