From: Joakim Tjernlund <Joakim.Tjernlund@infinera.com>
To: "danielwa@cisco.com" <danielwa@cisco.com>,
"dwmw2@infradead.org" <dwmw2@infradead.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"nkela@cisco.com" <nkela@cisco.com>,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
"xe-linux-external@cisco.com" <xe-linux-external@cisco.com>
Subject: Re: [PATCH] jffs2: implement mount option to configure endianness
Date: Wed, 7 Nov 2018 18:41:47 +0000 [thread overview]
Message-ID: <bee96cb5db73c325675881b180006e1382718abe.camel@infinera.com> (raw)
In-Reply-To: <df9cdf1753ec7e6e20c12aa096b98453.squirrel@twosheds.infradead.org>
On Wed, 2018-11-07 at 17:58 +0000, David Woodhouse wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
>
> > On Wed, Nov 07, 2018 at 04:12:14PM -0000, David Woodhouse wrote:
> > > > Yes, this may slow things down. I am not sure I agree with the impl.
> > > > either.
> > > > Could one not make cpu_to_je_X/jeX_to_cpu a function ptr which is set
> > > to
> > > > a func. with the correct endian?
> > >
> > > On x86 retpoline would make that quite slow.
retpoline aside, would it make a difference ?
> >
> > Is x86 the largest consumer of jffs2 ?
>
> Certainly not. I'm not sure which architectures do have Spectre V2
> mitigations which make indirect branches expensive now... perhaps there is
> no intersection with the cases where we really care about JFFS2 being
> CPU-bound?
All that passing of a new extra arg and extra if .. elif .. does cost too.
next prev parent reply other threads:[~2018-11-07 18:41 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-06 21:49 [PATCH] jffs2: implement mount option to configure endianness Nikunj Kela
2018-11-07 9:05 ` David Woodhouse
2018-11-07 9:16 ` Joakim Tjernlund
2018-11-07 16:12 ` David Woodhouse
2018-11-07 17:33 ` Daniel Walker
2018-11-07 17:58 ` David Woodhouse
2018-11-07 18:41 ` Joakim Tjernlund [this message]
2018-11-08 15:25 ` Christoph Hellwig
2018-11-07 19:21 ` Daniel Walker
2018-11-07 18:04 ` Nikunj Kela (nkela)
2018-11-07 18:14 ` Richard Weinberger
2018-11-08 8:11 ` David Woodhouse
2018-11-08 18:01 ` Nikunj Kela (nkela)
2018-11-08 18:50 ` Joakim Tjernlund
2018-11-08 19:47 ` David Woodhouse
2018-11-12 21:43 ` Daniel Walker
2018-11-12 22:50 ` Daniel Walker
2018-11-12 23:11 ` David Woodhouse
2018-11-12 23:40 ` Daniel Walker
2018-11-12 23:43 ` David Woodhouse
2018-11-13 0:06 ` Daniel Walker
2018-11-13 21:01 ` Daniel Walker
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