From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-sgx@vger.kernel.org, Haitao Huang <haitao.huang@linux.intel.com>
Subject: Re: [PATCH v4] x86/sgx: Fix deadlock and race conditions between fork() and EPC reclaim
Date: Tue, 14 Apr 2020 21:45:28 +0300 [thread overview]
Message-ID: <20200414184528.GA11185@linux.intel.com> (raw)
In-Reply-To: <20200414071743.GB8403@linux.intel.com>
On Tue, Apr 14, 2020 at 10:17:49AM +0300, Jarkko Sakkinen wrote:
> On Mon, Apr 13, 2020 at 09:32:34PM -0700, Sean Christopherson wrote:
> > On Mon, Apr 06, 2020 at 11:56:26PM +0300, Jarkko Sakkinen wrote:
> > > From: Sean Christopherson <sean.j.christopherson@intel.com>
> > spin_lock(&encl->mm_lock);
> > > +
> > > list_add_rcu(&encl_mm->list, &encl->mm_list);
> > > - spin_unlock(&encl->mm_lock);
> > >
> > > - synchronize_srcu(&encl->srcu);
> > > + /* Even if the CPU does not reorder writes, a compiler might. */
> >
> > The preferred (by maintainers) style of comment for smp_wmb()/smp_rmb()
> > comments is to explicitly call out the associated reader/writer. If you
> > want to go with a minimal comment, my vote is for something like:
> >
> > /*
> > * Add to list before updating version. Pairs the with smp_rmb() in
> > * sgx_reclaimer_block().
> > */
> >
> > And if you want to go really spartan, I'd take:
> >
> > /* Pairs with smp_rmb() in sgx_reclaimer_block(). */
> >
> > over a generic comment about the compiler reordering instructions.
>
> Thaks Sean, makes sense, I'll go with your "spartan" suggestion.
Updated, ready to squash?
/Jarkko
next prev parent reply other threads:[~2020-04-14 18:45 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-06 20:56 [PATCH v4] x86/sgx: Fix deadlock and race conditions between fork() and EPC reclaim Jarkko Sakkinen
2020-04-14 4:32 ` Sean Christopherson
2020-04-14 7:17 ` Jarkko Sakkinen
2020-04-14 18:45 ` Jarkko Sakkinen [this message]
2020-04-16 4:28 ` Sean Christopherson
2020-04-16 17:24 ` Jarkko Sakkinen
2020-04-16 17:39 ` Jarkko Sakkinen
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=20200414184528.GA11185@linux.intel.com \
--to=jarkko.sakkinen@linux.intel.com \
--cc=haitao.huang@linux.intel.com \
--cc=linux-sgx@vger.kernel.org \
--cc=sean.j.christopherson@intel.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 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).