linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
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 12:23:28 -0300	[thread overview]
Message-ID: <14da928d1cae8779a93228455c4873c127eeffa6.camel@gmail.com> (raw)
In-Reply-To: <20200624062411.367796-6-leobras.c@gmail.com>

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%
Averag
e write latency: -23.0%
Average read latency:  -2.26%



  reply	other threads:[~2020-06-26 15:29 UTC|newest]

Thread overview: 32+ 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
2020-07-01  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
2020-07-02  0:21       ` Alexey Kardashevskiy
2020-07-02  0:36         ` Leonardo Bras
2020-07-02  0:43           ` Alexey Kardashevskiy
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
2020-07-01  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
2020-07-02  0:18       ` Alexey Kardashevskiy
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
2020-07-02  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 [this message]
2020-06-26 17:55     ` Leonardo Bras
2020-07-01  8:16   ` Alexey Kardashevskiy
2020-07-01 19:57     ` Leonardo Bras
2020-07-01 23:48       ` Leonardo Bras
2020-07-02  0:31         ` Alexey Kardashevskiy
2020-07-02  0:54           ` Leonardo Bras
2020-07-03  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
2020-06-24 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=14da928d1cae8779a93228455c4873c127eeffa6.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).