Jordan Russell wrote:
On 6/16/2010 11:52 AM, Bill Davidsen wrote:
Alternatively, you can try setting your io scheduler to
deadline,
Wow - huge difference! No "hung task" warnings, no processes stuck in
"D" state; the system remains completely responsive throughout the
entire check.
I don't see why, though, processes are blocking for 2+ minutes on the
simplest of I/O operations when the default CFQ scheduler is used. Isn't
CFQ supposed to distribute I/O bandwidth in a "completely fair" manner?
Do md checks bypass the fairness algorithm?
The CFQ has its own idea of what is "fair" and works poorly (even
abysmally as you saw) for some load cases.
--
Bill Davidsen <davidsen@xxxxxxx>
"We can't solve today's problems by using the same thinking we
used in creating them." - Einstein
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
