From: Julien Grall <julien@xen.org>
To: "Dario Faggioli" <dfaggioli@suse.com>,
"Anders Törnqvist" <anders.tornqvist@codiax.se>,
xen-devel@lists.xenproject.org,
"Stefano Stabellini" <sstabellini@kernel.org>
Cc: Jan Beulich <jbeulich@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Juergen Gross <jgross@suse.com>
Subject: Re: Null scheduler and vwfi native problem
Date: Wed, 3 Feb 2021 09:19:06 +0000 [thread overview]
Message-ID: <1ab7ad80-c027-ffdd-8188-e1ab1fd53335@xen.org> (raw)
In-Reply-To: <501664dbdb736eaa4d9c05255dedfd7ad3e694fa.camel@suse.com>
Hi,
On 03/02/2021 07:31, Dario Faggioli wrote:
> On Tue, 2021-02-02 at 15:23 +0000, Julien Grall wrote:
>> In reality, it is probably still too early as a pCPU can be
>> considered
>> quiesced until a call to rcu_lock*() (such rcu_lock_domain()).
>>
> Well, yes, in theory, we could track down which is the first RCU read
> side crit. section on this path, and put the call right before that (if
> I understood what you mean).
Oh, that's not what I meant. This will indeed be far more complex than I
originally had in mind.
AFAIU, the RCU uses critical section to protect data. So the "entering"
could be used as "the pCPU is not quiesced" and "exiting" could be used
as "the pCPU is quiesced".
The concern with my approach is we would need to make sure that Xen
correctly uses the rcu helpers. I know Juergen worked on that recently,
but I don't know whether this is fully complete.
Cheers,
--
Julien Grall
next prev parent reply other threads:[~2021-02-03 9:19 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 10:54 Null scheduler and vwfi native problem Anders Törnqvist
2021-01-21 18:32 ` Dario Faggioli
2021-01-21 19:40 ` Julien Grall
2021-01-21 23:35 ` Dario Faggioli
2021-01-22 8:06 ` Anders Törnqvist
2021-01-22 9:05 ` Dario Faggioli
2021-01-22 14:26 ` Julien Grall
2021-01-22 17:44 ` Anders Törnqvist
2021-01-25 15:45 ` Dario Faggioli
2021-01-25 16:11 ` Dario Faggioli
2021-01-26 17:03 ` Anders Törnqvist
2021-01-26 22:31 ` Dario Faggioli
2021-01-29 8:08 ` Anders Törnqvist
2021-01-29 8:18 ` Jürgen Groß
2021-01-29 10:16 ` Dario Faggioli
2021-02-01 6:53 ` Anders Törnqvist
2021-01-30 17:59 ` Dario Faggioli
2021-02-01 6:55 ` Anders Törnqvist
2021-02-02 7:59 ` Julien Grall
2021-02-02 15:03 ` Dario Faggioli
2021-02-02 15:23 ` Julien Grall
2021-02-03 7:31 ` Dario Faggioli
2021-02-03 9:19 ` Julien Grall [this message]
2021-02-03 11:00 ` Jürgen Groß
2021-02-03 11:20 ` Julien Grall
2021-02-03 12:02 ` Jürgen Groß
2021-02-15 7:15 ` Anders Törnqvist
2021-01-22 14:02 ` Julien Grall
2021-01-22 17:30 ` Anders Törnqvist
2021-01-22 8:07 ` Anders Törnqvist
2021-01-21 19:16 ` Julien Grall
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=1ab7ad80-c027-ffdd-8188-e1ab1fd53335@xen.org \
--to=julien@xen.org \
--cc=anders.tornqvist@codiax.se \
--cc=andrew.cooper3@citrix.com \
--cc=dfaggioli@suse.com \
--cc=jbeulich@suse.com \
--cc=jgross@suse.com \
--cc=sstabellini@kernel.org \
--cc=xen-devel@lists.xenproject.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).