Messages in this thread | | | Date | Tue, 29 Mar 2005 22:50:10 -0600 | From | Robert Hancock <> | Subject | Re: Aligning file system data |
| |
John Richard Moser wrote: > How likely is it that I can actually align stuff to 31.5KiB on the > physical disk, i.e. have each block be a track?
I don't think this is very likely. Even being able to find out what the physical disk arrangement is, or whether it is consistent in terms of track size, etc. seems unlikely.
> > Rather than leveraging the track cache, would it be less expensive for > me to simply read in blocks totaling about 16 or 32KiB all at once?
For block sizes that small I think that the kernel should be smart enough to do this itself, there is no need to concern with such low level details in the application.
> How much more latency is involved in (B) than in (C)? Does crossing a > track boundary incur anything expensive?
Given that both the disk and the kernel will likely read far more than 32KB ahead I can't see much difference other than the overhead inside your application..
-- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.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/
| |