Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1;
Date:   Tue, 17 Oct 2023 00:39:32 +0300
From:   "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Joerg Roedel <jroedel@suse.de>,
        Ard Biesheuvel <ardb@kernel.org>,
        Andi Kleen <ak@linux.intel.com>,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        David Rientjes <rientjes@google.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Ingo Molnar <mingo@redhat.com>,
        Dario Faggioli <dfaggioli@suse.com>,
        Mike Rapoport <rppt@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        marcelo.cerri@canonical.com, tim.gardner@canonical.com,
        philip.cox@canonical.com, aarcange@redhat.com, peterx@redhat.com,
        x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev,
        linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
        stable@kernel.org, Nikolay Borisov <nik.borisov@suse.com>
Subject: Re: [PATCHv2] efi/unaccepted: Fix soft lockups caused by parallel
 memory acceptance
Message-ID: <20231016213932.6cscnn6tsnzsnvmf@box.shutemov.name>
References: <20231016163122.12855-1-kirill.shutemov@linux.intel.com>
 <ZS15HZqK4hu5NjSh@casper.infradead.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ZS15HZqK4hu5NjSh@casper.infradead.org>
Precedence: bulk

On Mon, Oct 16, 2023 at 06:55:41PM +0100, Matthew Wilcox wrote:
> On Mon, Oct 16, 2023 at 07:31:22PM +0300, Kirill A. Shutemov wrote:
> >   v2:
> >    - Fix deadlock (Vlastimil);
> >    - Fix comments (Vlastimil);
> >    - s/cond_resched()/cpu_relax()/ -- cond_resched() cannot be called
> >      from atomic context;
> 
> Isn't there an implicit cpu_relax() while we're spinning?  Does this
> really accomplish anything?

You are right. It is useless. I will drop it in v3.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov