From: oleg@redhat.com (Oleg Nesterov)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 2/5] x86,entry: Only call user_exit if TIF_NOHZ
Date: Thu, 31 Jul 2014 18:58:04 +0200 [thread overview]
Message-ID: <20140731165804.GB16800@redhat.com> (raw)
In-Reply-To: <20140731165423.GA16800@redhat.com>
On 07/31, Oleg Nesterov wrote:
>
> On 07/31, Frederic Weisbecker wrote:
> >
> > On Thu, Jul 31, 2014 at 06:42:46PM +0200, Oleg Nesterov wrote:
> > >
> > > And if we change this, then the code above becomes racy. The state of
> > > TIF_XYZ can be changed right after the check. OK, it is racy anyway ;)
> > > but still this adds more confusion.
> >
> > No because all running tasks have this flag set when context tracking is
> > enabled. And context tracking can't be disabled on runtime.
>
> Yes, yes, please note that I said "if we change this".
And "it is racy anyway" connects to the problems we discuss in another
thread.
Oleg.
next prev parent reply other threads:[~2014-07-31 16:58 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-29 3:38 [PATCH v4 0/5] x86: two-phase syscall tracing and seccomp fastpath Andy Lutomirski
2014-07-29 3:38 ` [PATCH v4 1/5] x86,x32,audit: Fix x32's AUDIT_ARCH wrt audit Andy Lutomirski
2014-07-29 3:38 ` [PATCH v4 2/5] x86,entry: Only call user_exit if TIF_NOHZ Andy Lutomirski
2014-07-29 19:32 ` Oleg Nesterov
2014-07-30 16:43 ` Frederic Weisbecker
2014-07-30 17:23 ` Andy Lutomirski
2014-07-31 15:16 ` Frederic Weisbecker
2014-07-31 16:42 ` Oleg Nesterov
2014-07-31 16:49 ` Frederic Weisbecker
2014-07-31 16:54 ` Oleg Nesterov
2014-07-31 16:58 ` Oleg Nesterov [this message]
2014-07-31 17:17 ` Frederic Weisbecker
2014-07-29 3:38 ` [PATCH v4 3/5] x86: Split syscall_trace_enter into two phases Andy Lutomirski
2014-07-29 19:25 ` Oleg Nesterov
2014-07-29 3:38 ` [PATCH v4 4/5] x86_64, entry: Treat regs->ax the same in fastpath and slowpath syscalls Andy Lutomirski
2014-07-29 3:38 ` [PATCH v4 5/5] x86_64, entry: Use split-phase syscall_trace_enter for 64-bit syscalls Andy Lutomirski
2014-07-29 19:20 ` [PATCH v4 0/5] x86: two-phase syscall tracing and seccomp fastpath Oleg Nesterov
2014-07-29 20:54 ` Andy Lutomirski
2014-07-29 23:30 ` Andy Lutomirski
2014-07-30 15:32 ` Oleg Nesterov
2014-07-30 16:59 ` Frederic Weisbecker
2014-07-30 17:25 ` Andy Lutomirski
2014-07-31 16:56 ` H. Peter Anvin
2014-07-31 17:20 ` Frederic Weisbecker
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=20140731165804.GB16800@redhat.com \
--to=oleg@redhat.com \
--cc=linux-arm-kernel@lists.infradead.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).