[patch] IPMI KCS can drop the lock while servicing a request
Alexander V. Chernikov
melifaro at FreeBSD.org
Mon Mar 25 14:31:42 UTC 2013
On 25.03.2013 02:38, Alexander V. Chernikov wrote:
> On 24.03.2013 07:11, Eric van Gyzen wrote:
>> At work, we discovered that our application's IPMI thread would often
>> use a lot of CPU time. The KCS thread uses DELAY to wait for the BMC, so
>> it can run without sleeping for a "long" time with a slow BMC. It also
>> holds the ipmi_softc.ipmi_lock during this time. When using adaptive
>> mutexes, an application thread that wants to operate on the
>> ipmi_pending_requests list will also spin during this same time.
> We suffer from the same problem, too.
>> We see no reason that the KCS thread needs to hold the lock while
>> servicing a request. We've been running with the attached patch for a
> Well, this seems to be true. I'll try to commit something like this
> patch in several days.
Done in r248705.
>> few months, with no ill effects.
>> freebsd-stable at freebsd.org mailing list
>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"
> freebsd-stable at freebsd.org mailing list
> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"
More information about the freebsd-stable