Date: Mon, 21 Oct 2013 11:28:34 -0700 From: John-Mark Gurney <jmg@funkthat.com> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: Andre Oppermann <andre@freebsd.org>, Mark R V Murray <mark@grondar.org>, freebsd-arch@freebsd.org Subject: Re: always load aesni or load it when cpu supports it Message-ID: <20131021182834.GX56872@funkthat.com> In-Reply-To: <37693.1382379728@critter.freebsd.dk> References: <20131020070022.GP56872@funkthat.com> <423D921D-6CE5-49D9-BCED-AB14EB236800@grondar.org> <20131020161634.GQ56872@funkthat.com> <5264F074.4010607@freebsd.org> <20131021164034.GU56872@funkthat.com> <37693.1382379728@critter.freebsd.dk>
next in thread | previous in thread | raw e-mail | index | archive | help
Poul-Henning Kamp wrote this message on Mon, Oct 21, 2013 at 18:22 +0000: > In message <20131021164034.GU56872@funkthat.com>, John-Mark Gurney writes: > > >The choice of 32 blocks (512 bytes) was arbitrary, but chosen because > >it is a disk sector size... If you're doing that much AES, on a slower > >machine, you'll probably want to use an accelerator... > > I'd say it is both arbitrary and pointless. > > Logical "disk-sectors" under both GBDE and GELI can be any size > (think RAID-5 stripe) and consumer harddisks have 4K sectors these days. > > Why do you fee a limit is necessary ? If you're on a slow system (embeded x86 or arm) that has an AES accelerator, you really want to be using your accelerator than wasting your cpu cycles on large blockes of AES... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20131021182834.GX56872>