From: Leonardo Bras <leobras.c@gmail.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>,
Ram Pai <linuxram@us.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 5/6] powerpc/pseries/iommu: Make use of DDW even if it does not map the partition
Date: Fri, 26 Jun 2020 14:55:41 -0300 [thread overview]
Message-ID: <d58faed1e9e35becb80f2737ed4be3d422507d6e.camel@gmail.com> (raw)
In-Reply-To: <14da928d1cae8779a93228455c4873c127eeffa6.camel@gmail.com>
On Fri, 2020-06-26 at 12:23 -0300, Leonardo Bras wrote:
> On Wed, 2020-06-24 at 03:24 -0300, Leonardo Bras wrote:
> > As of today, if a DDW is created and can't map the whole partition, it's
> > removed and the default DMA window "ibm,dma-window" is used instead.
> >
> > Usually this DDW is bigger than the default DMA window, so it would be
> > better to make use of it instead.
> >
> > Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
> > ---
>
> I tested this change with a 256GB DDW which did not map the whole
> partition, with a MT27700 Family [ConnectX-4 Virtual Function].
>
> I noticed the performance improvement is about the same as using DDW
> with IOMMU bypass.
>
> 64 thread write throughput: +203.0%
> 64 thread read throughput: +17.5%
> 1 thread write throughput: +20.5%
> 1 thread read throughput: +3.43%
> Average write latency: -23.0%
> Average read latency: -2.26%
The above improvements are based on the default DMA window, which is
currently used if DDW can't map the whole partition.
Those values are an average of 20 tests for each environment, 30
seconds each test.
I also did some intense testing, for 5 hour each:
64 thread write throughput
64 thread read throughput
The throughput values are stable in the whole test, and I noticed no
error on dmesg / journalctl.
next prev parent reply other threads:[~2020-06-26 17:55 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-24 6:24 [PATCH v2 0/6] Remove default DMA window before creating DDW Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm, ddw-applicable Leonardo Bras
2020-07-01 8:16 ` [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable Alexey Kardashevskiy
2020-07-01 13:28 ` Leonardo Bras
2020-07-01 13:28 ` Leonardo Bras
2020-07-02 0:21 ` Alexey Kardashevskiy
2020-07-02 0:36 ` Leonardo Bras
2020-07-02 0:36 ` Leonardo Bras
2020-07-02 0:43 ` Alexey Kardashevskiy
2020-07-02 0:46 ` Leonardo Bras
2020-07-02 0:46 ` Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 2/6] powerpc/pseries/iommu: Update call to ibm,query-pe-dma-windows Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 2/6] powerpc/pseries/iommu: Update call to ibm, query-pe-dma-windows Leonardo Bras
2020-07-01 8:17 ` [PATCH v2 2/6] powerpc/pseries/iommu: Update call to ibm,query-pe-dma-windows Alexey Kardashevskiy
2020-07-01 14:04 ` Leonardo Bras
2020-07-01 14:04 ` Leonardo Bras
2020-07-02 0:18 ` Alexey Kardashevskiy
2020-07-02 0:28 ` Leonardo Bras
2020-07-02 0:28 ` Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 3/6] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 4/6] powerpc/pseries/iommu: Remove default DMA window before creating DDW Leonardo Bras
2020-07-01 8:17 ` Alexey Kardashevskiy
2020-07-01 19:48 ` Leonardo Bras
2020-07-01 19:48 ` Leonardo Bras
2020-07-02 0:25 ` Alexey Kardashevskiy
2020-06-24 6:24 ` [PATCH v2 5/6] powerpc/pseries/iommu: Make use of DDW even if it does not map the partition Leonardo Bras
2020-06-26 15:23 ` Leonardo Bras
2020-06-26 17:55 ` Leonardo Bras [this message]
2020-07-01 8:16 ` Alexey Kardashevskiy
2020-07-01 19:57 ` Leonardo Bras
2020-07-01 19:57 ` Leonardo Bras
2020-07-01 23:48 ` Leonardo Bras
2020-07-01 23:48 ` Leonardo Bras
2020-07-02 0:31 ` Alexey Kardashevskiy
2020-07-02 0:54 ` Leonardo Bras
2020-07-02 0:54 ` Leonardo Bras
2020-07-03 6:27 ` Leonardo Bras
2020-07-03 6:27 ` Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 6/6] powerpc/pseries/iommu: Avoid errors when DDW starts at 0x00 Leonardo Bras
2020-06-26 17:46 ` Leonardo Bras
2020-07-01 8:04 ` Alexey Kardashevskiy
2020-07-01 19:59 ` Leonardo Bras
2020-07-01 19:59 ` Leonardo Bras
2020-06-24 15:54 ` [PATCH v2 0/6] Remove default DMA window before creating DDW Leonardo Bras
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d58faed1e9e35becb80f2737ed4be3d422507d6e.camel@gmail.com \
--to=leobras.c@gmail.com \
--cc=aik@ozlabs.ru \
--cc=bauerman@linux.ibm.com \
--cc=benh@kernel.crashing.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=linuxram@us.ibm.com \
--cc=mpe@ellerman.id.au \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.