All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andrea Parri <andrea.parri@amarulasolutions.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: David Howells <dhowells@redhat.com>,
	viro@zeniv.linux.org.uk, raven@themaw.net,
	linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
	linux-block@vger.kernel.org, keyrings@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Will Deacon <will.deacon@arm.com>,
	"Paul E. McKenney" <paulmck@linux.ibm.com>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH 1/7] General notification queue with user mmap()'able ring buffer
Date: Thu, 30 May 2019 11:50:39 +0200	[thread overview]
Message-ID: <20190530095039.GA5137@andrea> (raw)
In-Reply-To: <20190529231112.GB3164@kroah.com>

> > Looking at the perf ring buffer, there appears to be a missing barrier in
> > perf_aux_output_end():
> > 
> > 	rb->user_page->aux_head = rb->aux_head;
> > 
> > should be:
> > 
> > 	smp_store_release(&rb->user_page->aux_head, rb->aux_head);
> > 
> > It should also be using smp_load_acquire().  See
> > Documentation/core-api/circular-buffers.rst
> > 
> > And a (partial) patch has been proposed: https://lkml.org/lkml/2018/5/10/249
> 
> So, if that's all that needs to be fixed, can you use the same
> buffer/code if that patch is merged?

That's about one year old...: let me add the usual suspects in Cc:  ;-)
since I'm not sure what the plan was (or if I'm missing something) ...

Speaking of ring buffer implementations (and relatively "old" patches),
here's another quite interesting:

  https://lkml.kernel.org/r/20181211034032.32338-1-yuleixzhang@tencent.com

Thanks,
  Andrea

WARNING: multiple messages have this Message-ID (diff)
From: Andrea Parri <andrea.parri@amarulasolutions.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: David Howells <dhowells@redhat.com>,
	viro@zeniv.linux.org.uk, raven@themaw.net,
	linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
	linux-block@vger.kernel.org, keyrings@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Will Deacon <will.deacon@arm.com>,
	"Paul E. McKenney" <paulmck@linux.ibm.com>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH 1/7] General notification queue with user mmap()'able ring buffer
Date: Thu, 30 May 2019 09:50:39 +0000	[thread overview]
Message-ID: <20190530095039.GA5137@andrea> (raw)
In-Reply-To: <20190529231112.GB3164@kroah.com>

> > Looking at the perf ring buffer, there appears to be a missing barrier in
> > perf_aux_output_end():
> > 
> > 	rb->user_page->aux_head = rb->aux_head;
> > 
> > should be:
> > 
> > 	smp_store_release(&rb->user_page->aux_head, rb->aux_head);
> > 
> > It should also be using smp_load_acquire().  See
> > Documentation/core-api/circular-buffers.rst
> > 
> > And a (partial) patch has been proposed: https://lkml.org/lkml/2018/5/10/249
> 
> So, if that's all that needs to be fixed, can you use the same
> buffer/code if that patch is merged?

That's about one year old...: let me add the usual suspects in Cc:  ;-)
since I'm not sure what the plan was (or if I'm missing something) ...

Speaking of ring buffer implementations (and relatively "old" patches),
here's another quite interesting:

  https://lkml.kernel.org/r/20181211034032.32338-1-yuleixzhang@tencent.com

Thanks,
  Andrea

  reply	other threads:[~2019-05-30  9:50 UTC|newest]

Thread overview: 131+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-28 16:01 [RFC][PATCH 0/7] Mount, FS, Block and Keyrings notifications David Howells
2019-05-28 16:01 ` David Howells
2019-05-28 16:01 ` [PATCH 1/7] General notification queue with user mmap()'able ring buffer David Howells
2019-05-28 16:01   ` David Howells
2019-05-28 16:26   ` Greg KH
2019-05-28 16:26     ` Greg KH
2019-05-28 17:30   ` David Howells
2019-05-28 17:30     ` David Howells
2019-05-28 23:12     ` Greg KH
2019-05-28 23:12       ` Greg KH
2019-05-29 16:06     ` David Howells
2019-05-29 16:06       ` David Howells
2019-05-29 17:46       ` Jann Horn
2019-05-29 17:46         ` Jann Horn
2019-05-29 21:02       ` David Howells
2019-05-29 21:02         ` David Howells
2019-05-31 11:14         ` Peter Zijlstra
2019-05-31 11:14           ` Peter Zijlstra
2019-05-31 12:02         ` David Howells
2019-05-31 12:02           ` David Howells
2019-05-31 13:26           ` Peter Zijlstra
2019-05-31 13:26             ` Peter Zijlstra
2019-05-31 14:20           ` David Howells
2019-05-31 14:20             ` David Howells
2019-05-31 16:44             ` Peter Zijlstra
2019-05-31 16:44               ` Peter Zijlstra
2019-05-31 17:12             ` David Howells
2019-05-31 17:12               ` David Howells
2019-06-17 16:24               ` Peter Zijlstra
2019-06-17 16:24                 ` Peter Zijlstra
2019-05-29 23:09       ` Greg KH
2019-05-29 23:09         ` Greg KH
2019-05-29 23:11       ` Greg KH
2019-05-29 23:11         ` Greg KH
2019-05-30  9:50         ` Andrea Parri [this message]
2019-05-30  9:50           ` Andrea Parri
2019-05-31  8:35           ` Peter Zijlstra
2019-05-31  8:35             ` Peter Zijlstra
2019-05-31  8:47       ` Peter Zijlstra
2019-05-31  8:47         ` Peter Zijlstra
2019-05-31 12:42       ` David Howells
2019-05-31 12:42         ` David Howells
2019-05-31 14:55       ` David Howells
2019-05-31 14:55         ` David Howells
2019-05-28 19:14   ` Jann Horn
2019-05-28 19:14     ` Jann Horn
2019-05-28 22:28   ` David Howells
2019-05-28 22:28     ` David Howells
2019-05-28 23:16     ` Jann Horn
2019-05-28 23:16       ` Jann Horn
2019-05-28 16:02 ` [PATCH 2/7] keys: Add a notification facility David Howells
2019-05-28 16:02   ` David Howells
2019-05-28 16:02 ` [PATCH 3/7] vfs: Add a mount-notification facility David Howells
2019-05-28 16:02   ` David Howells
2019-05-28 20:06   ` Jann Horn
2019-05-28 20:06     ` Jann Horn
2019-05-28 23:04   ` David Howells
2019-05-28 23:04     ` David Howells
2019-05-28 23:23     ` Jann Horn
2019-05-28 23:23       ` Jann Horn
2019-05-29 11:16     ` David Howells
2019-05-29 11:16       ` David Howells
2019-05-28 23:08   ` David Howells
2019-05-28 23:08     ` David Howells
2019-05-29 10:55   ` David Howells
2019-05-29 10:55     ` David Howells
2019-05-29 11:00   ` David Howells
2019-05-29 11:00     ` David Howells
2019-05-29 15:53     ` Casey Schaufler
2019-05-29 15:53       ` Casey Schaufler
2019-05-29 16:12       ` Jann Horn
2019-05-29 16:12         ` Jann Horn
2019-05-29 17:04         ` Casey Schaufler
2019-05-29 17:04           ` Casey Schaufler
2019-06-03 16:30         ` David Howells
2019-06-03 16:30           ` David Howells
2019-05-29 17:13       ` Andy Lutomirski
2019-05-29 17:13         ` Andy Lutomirski
2019-05-29 17:46         ` Casey Schaufler
2019-05-29 17:46           ` Casey Schaufler
2019-05-29 18:11           ` Jann Horn
2019-05-29 18:11             ` Jann Horn
2019-05-29 19:28             ` Casey Schaufler
2019-05-29 19:28               ` Casey Schaufler
2019-05-29 19:47               ` Jann Horn
2019-05-29 19:47                 ` Jann Horn
2019-05-29 20:50                 ` Casey Schaufler
2019-05-29 20:50                   ` Casey Schaufler
2019-05-29 23:12           ` Andy Lutomirski
2019-05-29 23:12             ` Andy Lutomirski
2019-05-29 23:56             ` Casey Schaufler
2019-05-29 23:56               ` Casey Schaufler
2019-05-28 16:02 ` [PATCH 4/7] vfs: Add superblock notifications David Howells
2019-05-28 16:02   ` David Howells
2019-05-28 20:27   ` Jann Horn
2019-05-28 20:27     ` Jann Horn
2019-05-29 12:58   ` David Howells
2019-05-29 12:58     ` David Howells
2019-05-29 14:16     ` Jann Horn
2019-05-29 14:16       ` Jann Horn
2019-05-28 16:02 ` [PATCH 5/7] fsinfo: Export superblock notification counter David Howells
2019-05-28 16:02   ` David Howells
2019-05-28 16:02 ` [PATCH 6/7] block: Add block layer notifications David Howells
2019-05-28 16:02   ` David Howells
2019-05-28 20:37   ` Jann Horn
2019-05-28 20:37     ` Jann Horn
2019-05-28 16:02 ` [PATCH 7/7] Add sample notification program David Howells
2019-05-28 16:02   ` David Howells
2019-05-28 23:58 ` [RFC][PATCH 0/7] Mount, FS, Block and Keyrings notifications Greg KH
2019-05-28 23:58   ` Greg KH
2019-05-29  6:33 ` Amir Goldstein
2019-05-29  6:33   ` Amir Goldstein
2019-05-29  6:33   ` Amir Goldstein
2019-05-29 14:25   ` Jan Kara
2019-05-29 14:25     ` Jan Kara
2019-05-29 15:10     ` Greg KH
2019-05-29 15:10       ` Greg KH
2019-05-29 15:53     ` Amir Goldstein
2019-05-29 15:53       ` Amir Goldstein
2019-05-30 11:00       ` Jan Kara
2019-05-30 11:00         ` Jan Kara
2019-06-04 12:33     ` David Howells
2019-06-04 12:33       ` David Howells
2019-05-29  6:45 ` David Howells
2019-05-29  6:45   ` David Howells
2019-05-29  7:40   ` Amir Goldstein
2019-05-29  7:40     ` Amir Goldstein
2019-05-29  9:09 ` David Howells
2019-05-29  9:09   ` David Howells
2019-05-29 15:41   ` Casey Schaufler
2019-05-29 15:41     ` Casey Schaufler

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=20190530095039.GA5137@andrea \
    --to=andrea.parri@amarulasolutions.com \
    --cc=dhowells@redhat.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=keyrings@vger.kernel.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=paulmck@linux.ibm.com \
    --cc=peterz@infradead.org \
    --cc=raven@themaw.net \
    --cc=viro@zeniv.linux.org.uk \
    --cc=will.deacon@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 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.