Re: dtrace/cyclic deadlock

2010-11-23 Thread Andriy Gapon
on 23/11/2010 08:33 Andriy Gapon said the following: > I think that this is quite similar to what we do for per-CPU caches in UMA and > so the same approach should work here. > That is, as in (Open)Solaris, the data should be accessed only from the owning > CPU and spinlock_enter()/spinlock_exit()

Re: Best way to determine if an IRQ is present

2010-11-23 Thread Andriy Gapon
on 22/11/2010 16:24 John Baldwin said the following: > Well, the real solution is actually larger than described in the PR. What > you > really want to do is take the logical CPUs offline when they are "halted". > Taking a CPU offline should trigger an EVENTHANDLER that various bits of code >

UFS Snapshots and iowait

2010-11-23 Thread Chris St Denis
I have started using "mount -u -o snapshot" as part of my backup process in order to have a week worth of local differential backups to allow quick and easy recovery of lost/overwritten/etc files. The snapshot of the partition (~250G and 2.3 million inodes used. ~10GB of data change per day) t

Re: UFS Snapshots and iowait

2010-11-23 Thread Kurt Lidl
On Tue, Nov 23, 2010 at 10:38:31AM -0800, Chris St Denis wrote: > Is this just due to the very high io bandwidth usage associated with > making a snapshot, or does the creation of this snapshot completely > block IO writes for around 5 minutes? It blocks updates to the filesystem while during pa

Re: [call for testing] userland debug symbols

2010-11-23 Thread Mark Johnston
On Tue, Nov 16, 2010 at 03:57:45PM -0500, Mark Johnston wrote: > Hello all, > > I've been sitting on my changes for a while, but I think they're ready > for testing at this point. They are described here: > > http://lists.freebsd.org/pipermail/freebsd-hackers/2010-November/033474.html > > Some m

Re: UFS Snapshots and iowait

2010-11-23 Thread krad
On 23 November 2010 19:49, Kurt Lidl wrote: > On Tue, Nov 23, 2010 at 10:38:31AM -0800, Chris St Denis wrote: > > Is this just due to the very high io bandwidth usage associated with > > making a snapshot, or does the creation of this snapshot completely > > block IO writes for around 5 minutes?

Re: PostgreSQL performance scaling

2010-11-23 Thread Luis Neves
On 11/22/2010 12:21 AM, Ivan Voras wrote: The "semwait" part is from PostgreSQL - probably shared buffer locking, but there's a large number of processes regularly in sbwait - maybe something can be optimized here? I think this paper was mentioned before, did you read it?... "An Analysis of L