linux-kernel - Re: [RFC][PATCH v2 08/11] context_tracking,rcu: Replace RCU dynticks counter with context

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210929194540.GZ880162@paulmck-ThinkPad-P17-Gen-1>
Date:   Wed, 29 Sep 2021 12:45:40 -0700
From:   "Paul E. McKenney" <paulmck@...nel.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     gor@...ux.ibm.com, jpoimboe@...hat.com, jikos@...nel.org,
        mbenes@...e.cz, pmladek@...e.com, mingo@...nel.org,
        linux-kernel@...r.kernel.org, joe.lawrence@...hat.com,
        fweisbec@...il.com, tglx@...utronix.de, hca@...ux.ibm.com,
        svens@...ux.ibm.com, sumanthk@...ux.ibm.com,
        live-patching@...r.kernel.org, rostedt@...dmis.org, x86@...nel.org
Subject: Re: [RFC][PATCH v2 08/11] context_tracking,rcu: Replace RCU dynticks
 counter with context_tracking

On Wed, Sep 29, 2021 at 09:24:31PM +0200, Peter Zijlstra wrote:
> On Wed, Sep 29, 2021 at 09:13:26PM +0200, Peter Zijlstra wrote:
> > On Wed, Sep 29, 2021 at 11:37:01AM -0700, Paul E. McKenney wrote:
> > 
> > > And what happens to all of this in !CONFIG_CONTEXT_TRACKING kernels?
> > > Of course, RCU needs it unconditionally.  (There appear to be at least
> > > parts of it that are unconditionally available, but I figured that I
> > > should ask.  Especially given the !CONFIG_CONTEXT_TRACKING definition
> > > of the __context_tracking_cpu_seq() function.)
> > 
> > For !CONFIG_CONTEXT_TRACKING it goes *poof*.
> > 
> > Since the thing was called dynticks, I presumed it was actually dynticks
> > only, silly me (also, I didn't see any obvious !context_tracking usage
> > of it, i'll go audit it more carefully.
> 
> Oh argh, it does idle too... damn. And I don't suppose having 2 counters
> is going to be nice :/
> 
> I'll go back to thinking about this.

Glad I could help?  For some definition of "help"?  ;-)

							Thanx, Paul