BerkeleyDB Hash vs Btree on FreeBSD and Linux
Hello. I noticed that BerkeleyDB Hash is VERY slow compared to BerkeleyDB Btree on FreeBSD (UFS or ZFS). But they (Hash and Btree) have roughly the same performance on Linux. Why? ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: BerkeleyDB Hash vs Btree on FreeBSD and Linux
On Wed, Jul 1, 2020 at 6:07 PM Nick Kostirya via freebsd-stable wrote: > > Hello. > > I noticed that BerkeleyDB Hash is VERY slow compared to BerkeleyDB Btree on > FreeBSD (UFS or ZFS). > But they (Hash and Btree) have roughly the same performance on Linux. > > Why? It's not an easy question, do you have more information about the test environment setup, and the statistics of the results? I'd recommend using some analysis tools like DTrace to check what it's busy for. Li-Wen ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: BerkeleyDB Hash vs Btree on FreeBSD and Linux
On Wed, 1 Jul 2020 18:20:19 +0800
Li-Wen Hsu wrote:
> On Wed, Jul 1, 2020 at 6:07 PM Nick Kostirya via freebsd-stable
> wrote:
> >
> > Hello.
> >
> > I noticed that BerkeleyDB Hash is VERY slow compared to BerkeleyDB Btree on
> > FreeBSD (UFS or ZFS).
> > But they (Hash and Btree) have roughly the same performance on Linux.
> >
> > Why?
>
> It's not an easy question, do you have more information about the test
> environment setup, and the statistics of the results?
>
> I'd recommend using some analysis tools like DTrace to check what it's busy
> for.
The top show getblk status often.
Please tell me what you can and how to look with DTrace.
I use
dtrace -n '::: /execname == "a.out"/ { @[probefunc] = count(); }'
but I do not see the difference between Hash and Btree.
___
freebsd-stable@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: BerkeleyDB Hash vs Btree on FreeBSD and Linux
On Wed, Jul 1, 2020 at 8:07 PM Nick Kostirya via freebsd-stable
wrote:
>
> On Wed, 1 Jul 2020 18:20:19 +0800
> Li-Wen Hsu wrote:
>
> > On Wed, Jul 1, 2020 at 6:07 PM Nick Kostirya via freebsd-stable
> > wrote:
> > >
> > > Hello.
> > >
> > > I noticed that BerkeleyDB Hash is VERY slow compared to BerkeleyDB Btree
> > > on FreeBSD (UFS or ZFS).
> > > But they (Hash and Btree) have roughly the same performance on Linux.
> > >
> > > Why?
> >
> > It's not an easy question, do you have more information about the test
> > environment setup, and the statistics of the results?
Any information about this?
> > I'd recommend using some analysis tools like DTrace to check what it's busy
> > for.
>
>
> The top show getblk status often.
>
> Please tell me what you can and how to look with DTrace.
>
> I use
> dtrace -n '::: /execname == "a.out"/ { @[probefunc] = count(); }'
>
> but I do not see the difference between Hash and Btree.
I would say check the flame graph:
http://www.brendangregg.com/blog/2015-03-10/freebsd-flame-graphs.html
There is benchmarks/flamegraph port but I haven't used it for a while.
Li-Wen
___
freebsd-stable@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
