linux-kernel - Re: [PATCH v4 4/4] PCI: Limit pci_alloc_irq

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: <078e659e-d151-5bc2-a7dd-fe0070267cb3@redhat.com>
Date:   Tue, 20 Oct 2020 09:00:01 -0400
From:   Nitesh Narayan Lal <nitesh@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>,
        Marcelo Tosatti <mtosatti@...hat.com>
Cc:     linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        linux-pci@...r.kernel.org, intel-wired-lan@...ts.osuosl.org,
        frederic@...nel.org, sassmann@...hat.com,
        jesse.brandeburg@...el.com, lihong.yang@...el.com,
        helgaas@...nel.org, jeffrey.t.kirsher@...el.com,
        jacob.e.keller@...el.com, jlelli@...hat.com, hch@...radead.org,
        bhelgaas@...gle.com, mike.marciniszyn@...el.com,
        dennis.dalessandro@...el.com, thomas.lendacky@....com,
        jiri@...dia.com, mingo@...hat.com, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, lgoncalv@...hat.com
Subject: Re: [PATCH v4 4/4] PCI: Limit pci_alloc_irq_vectors() to housekeeping
 CPUs


On 10/20/20 3:30 AM, Peter Zijlstra wrote:
> On Mon, Oct 19, 2020 at 11:00:05AM -0300, Marcelo Tosatti wrote:
>>> So I think it is important to figure out what that driver really wants
>>> in the nohz_full case. If it wants to retain N interrupts per CPU, and
>>> only reduce the number of CPUs, the proposed interface is wrong.
>> It wants N interrupts per non-isolated (AKA housekeeping) CPU.
> Then the patch is wrong and the interface needs changing from @min_vecs,
> @max_vecs to something that expresses the N*nr_cpus relation.

Reading Marcelo's comment again I think what is really expected is 1
interrupt per non-isolated (housekeeping) CPU (not N interrupts).

My bad that I missed it initially.

-- 
Thanks
Nitesh



Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)