linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org,
	"Alexey Kardashevskiy" <aik@ozlabs.ru>,
	linuxppc-dev@lists.ozlabs.org,
	"Lu Baolu" <baolu.lu@linux.intel.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Joerg Roedel" <joro@8bytes.org>,
	"Robin Murphy" <robin.murphy@arm.com>,
	"Björn Töpel" <bjorn.topel@gmail.com>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	linux-kernel@vger.kernel.org, brouer@redhat.com
Subject: Re: generic DMA bypass flag v4
Date: Fri, 10 Jul 2020 15:26:58 +0200	[thread overview]
Message-ID: <20200710152658.31a9391a@carbon> (raw)
In-Reply-To: <20200708152449.316476-1-hch@lst.de>

On Wed,  8 Jul 2020 17:24:44 +0200
Christoph Hellwig <hch@lst.de> wrote:

> Note that as-is this breaks the XSK buffer pool, which unfortunately
> poked directly into DMA internals.  A fix for that is already queued
> up in the netdev tree.
> 
> Jesper and XDP gang: this should not regress any performance as
> the dma-direct calls are now inlined into the out of line DMA mapping
> calls.  But if you can verify the performance numbers that would be
> greatly appreciated.

From a superficial review of the patches, they look okay to me. I don't
have time to run a performance benchmark (before I go on vacation).

I hoped Björn could test/benchmark this(?), given (as mentioned) this
also affect XSK / AF_XDP performance.

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer


      parent reply	other threads:[~2020-07-10 13:27 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-08 15:24 generic DMA bypass flag v4 Christoph Hellwig
2020-07-08 15:24 ` [PATCH 1/5] dma-mapping: move the remaining DMA API calls out of line Christoph Hellwig
2020-07-08 15:24 ` [PATCH 2/5] dma-mapping: inline the fast path dma-direct calls Christoph Hellwig
2020-07-08 15:24 ` [PATCH 3/5] dma-mapping: make support for dma ops optional Christoph Hellwig
2020-07-18 17:17   ` Guenter Roeck
2020-07-20  6:20     ` Christoph Hellwig
2020-07-08 15:24 ` [PATCH 4/5] dma-mapping: add a dma_ops_bypass flag to struct device Christoph Hellwig
2020-07-13  4:59   ` Alexey Kardashevskiy
2020-07-14  7:07     ` Christoph Hellwig
2020-07-14  7:12       ` Alexey Kardashevskiy
2020-07-08 15:24 ` [PATCH 5/5] powerpc: use the generic dma_ops_bypass mode Christoph Hellwig
2020-08-30  9:04   ` Cédric Le Goater
2020-08-31  6:40     ` Christoph Hellwig
2020-08-31  7:19       ` Cédric Le Goater
2020-09-05 15:45       ` Alexey Kardashevskiy
2020-07-10 13:26 ` Jesper Dangaard Brouer [this message]

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=20200710152658.31a9391a@carbon \
    --to=brouer@redhat.com \
    --cc=aik@ozlabs.ru \
    --cc=baolu.lu@linux.intel.com \
    --cc=bjorn.topel@gmail.com \
    --cc=daniel@iogearbox.net \
    --cc=gregkh@linuxfoundation.org \
    --cc=hch@lst.de \
    --cc=iommu@lists.linux-foundation.org \
    --cc=joro@8bytes.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=robin.murphy@arm.com \
    /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).