Re: write alignment matters?

[mlelstv%serpens.de@localhost (Michael van Elst)]

fair%NetBSD.org@localhost (Erik Fair) writes:

>On Jun 23, 2011, at 23:19 , Michael van Elst wrote:

>> smb%cs.columbia.edu@localhost (Steven Bellovin) writes:
>> 
>>> The point is that when dealing with raw devices, you take what the hardware
>>> gives you.  6th Edition could have detected this and copied the user data
>>> into a properly-aligned buffer, with the corresponding performance hit.
>>> Instead, it said "this is the way the hardware works; adapt".
>> 
>> I bet at that time block devices were still usuable...

>Define "unusable"?

Similar to raw devices in performance, I/O caching, and without the
hardware constraints regarding block sizes or alignment. I.e. something
that lets you treat disk contents like a regular file.

>Of course, if you want to talk about really slow I/O with massive latency, 
>let's talk about random access to DECtapes ...

Oh, I was talking about current NetBSD where block devices are a
second class citizen, soon to be abolished if someone finds enough
round tuits.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."