DMA Engine development
 help / color / mirror / Atom feed
From: Dave Hansen <dave.hansen@intel.com>
To: Boqun Feng <boqun.feng@gmail.com>, Mark Rutland <mark.rutland@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>, Vinod Koul <vkoul@kernel.org>,
	Dave Jiang <dave.jiang@intel.com>,
	dmaengine@vger.kernel.org,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Nikhil Rao <nikhil.rao@intel.com>, Tony Zhu <tony.zhu@intel.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org
Subject: Re: [PATCH] dmaengine: idxd: Change wmb() to smp_wmb() when copying completion record to user space
Date: Tue, 30 Jan 2024 12:30:56 -0800	[thread overview]
Message-ID: <388be136-f91c-403a-99e1-7a10c5bf9691@intel.com> (raw)
In-Reply-To: <ZblTystHpVkvjbkv@boqun-archlinux>

On 1/30/24 11:53, Boqun Feng wrote:
>>> Fixes: b022f59725f0 ("dmaengine: idxd: add idxd_copy_cr() to copy user completion record during page fault handling")
>>> Suggested-by: Nikhil Rao <nikhil.rao@intel.com>
>>> Tested-by: Tony Zhu <tony.zhu@intel.com>
> Since it has a "Fixes" tag and a "Tested-by" tag, I'd assume there has
> been a test w/ and w/o this patch showing it can resolve a real issue
> *constantly*? If so, I think x86 might be broken somewhere.
> 
> [Cc x86 maintainers]

Fenghua, could you perhaps explain how this problem affects end users?
What symptom was observed that made it obvious something was broken and
what changes with this patch?

  reply	other threads:[~2024-01-30 20:30 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-30  2:58 [PATCH] dmaengine: idxd: Change wmb() to smp_wmb() when copying completion record to user space Fenghua Yu
2024-01-30 15:35 ` Dave Jiang
2024-01-30 16:01 ` Lijun Pan
2024-01-30 17:58 ` Mark Rutland
2024-01-30 18:14   ` Mark Rutland
2024-01-30 19:53   ` Boqun Feng
2024-01-30 20:30     ` Dave Hansen [this message]
2024-01-30 20:41       ` Fenghua Yu
2024-01-31  4:18         ` Rao, Nikhil

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=388be136-f91c-403a-99e1-7a10c5bf9691@intel.com \
    --to=dave.hansen@intel.com \
    --cc=boqun.feng@gmail.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=dave.jiang@intel.com \
    --cc=dmaengine@vger.kernel.org \
    --cc=fenghua.yu@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@redhat.com \
    --cc=nikhil.rao@intel.com \
    --cc=tglx@linutronix.de \
    --cc=tony.zhu@intel.com \
    --cc=vkoul@kernel.org \
    --cc=x86@kernel.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