linux-kernel - Re: [PATCH] swiotlb: set IO TLB segment size via cmdline

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: <CADu_u-OjpYB0-B=tLKYsZH=auvQF-o7PJb-11W=1emY8jaA-mg@mail.gmail.com>
Date:   Thu, 16 Sep 2021 12:40:28 +0300
From:   Roman Skakun <rm.skakun@...il.com>
To:     Stefano Stabellini <sstabellini@...nel.org>
Cc:     Jan Beulich <jbeulich@...e.com>,
        Andrii Anisov <andrii_anisov@...m.com>,
        Roman Skakun <roman_skakun@...m.com>,
        Jonathan Corbet <corbet@....net>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Michael Ellerman <mpe@...erman.id.au>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Robin Murphy <robin.murphy@....com>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Randy Dunlap <rdunlap@...radead.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "Maciej W. Rozycki" <macro@...am.me.uk>,
        Muchun Song <songmuchun@...edance.com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Lu Baolu <baolu.lu@...ux.intel.com>,
        Mike Rapoport <rppt@...nel.org>, Will Deacon <will@...nel.org>,
        xen-devel@...ts.xenproject.org, linux-mips@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org, linux-doc@...r.kernel.org,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        iommu <iommu@...ts.linux-foundation.org>,
        Christoph Hellwig <hch@....de>
Subject: Re: [PATCH] swiotlb: set IO TLB segment size via cmdline

Hi Stefano,

> Also, Option 1 listed in the webpage seems to be a lot better. Any
> reason you can't do that? Because that option both solves the problem
> and increases performance.

Yes, Option 1 is probably more efficient.
But I use another platform under Xen without DMA adjustment functionality.
I pinned this webpage only for example to describe the similar problem I had.

Cheers,
Roman

ср, 15 сент. 2021 г. в 04:51, Stefano Stabellini <sstabellini@...nel.org>:

>
> On Tue, 14 Sep 2021, Christoph Hellwig wrote:
> > On Tue, Sep 14, 2021 at 05:29:07PM +0200, Jan Beulich wrote:
> > > I'm not convinced the swiotlb use describe there falls under "intended
> > > use" - mapping a 1280x720 framebuffer in a single chunk? (As an aside,
> > > the bottom of this page is also confusing, as following "Then we can
> > > confirm the modified swiotlb size in the boot log:" there is a log
> > > fragment showing the same original size of 64Mb.
> >
> > It doesn't.  We also do not add hacks to the kernel for whacky out
> > of tree modules.
>
> Also, Option 1 listed in the webpage seems to be a lot better. Any
> reason you can't do that? Because that option both solves the problem
> and increases performance.



--
Best Regards, Roman.