Looks like this one fell off the radar too, could you apply it now?
On 3/5/2012 9:17 PM, Phillip Susi wrote:
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On 03/01/2012 12:50 PM, Jim Meyering wrote:
Hi Phillip,
Can you describe, or better still, tell me how to demonstrate the
problem this is fixing? Or can you at least give a few details, like
which kernel you used, which command invoked and which values you got
for the two *_io variables?
I have a server with a 4 disk mdadm raid5 that has an optimal value of
1.5 MiB as a result of the 512k stripe factor. The current default
stripe factor is 512k but it used to be 64k. If you used a 64k stripe
factor that would give an optimal value of 192k with a 4 disk raid5.
I think your description was somehow negated, since it's the reverse
actually: it accepts a nonzero kernel alignment A only if 2^20 % A == 0.
I.e., that requires A<= 1024^2. A kernel alignment value larger
than 1024^2 is ignored.
You are right, the comment was wrong. Try this instead:
There were several apparently incorrect tests that would cause the
kernel supplied optimal io size to be discarded in favor of the default
1 MiB alignment. As written, it would only accept values less than the
parted default ( 1 MiB ) that were also an even power of two. For
example, 128k or 512k would be accepted, but 192k or 1.5 MiB would be
ignored.
