Phillip Susi wrote:
This discussion seems to involve two different solutions to two
different problems. If it is a simple counter you want to be able to
poll, then sysfs/debugfs is an appropriate place to make the count
available. If it is a detailed log of IO requests that you are after,
then blktrace is appropriate.
It's about counters ... well, sometimes a buch of counters called
histogram.
I did not read the patch to see, so I must ask: does it merely keep
statistics or does it log events? If it is just statistics you are
after, then clearly blktrace is not the appropriate tool to use.
If matters were as simple as that, sigh.
Statistics feed on data reported through events.
"Oh, this request has completed - time to update I/O counters."
The tricky question is: is event processing, that is, statistics data
aggregation, better done later (in user space), or immediately
(in the kernel). Both approaches exist: blktrace/btt vs.
gendisk statistics used by iostat, for example.
My feeling was that the in-kernel counters approach of my patch
was fine with regard to the purpose of these statistics. But blktrace
exists, undeniably, and deserves a closer look.
Martin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
