Re: RFC: Removing hpt* drivers from GENERIC

From: Colin Percival <cperciva_at_tarsnap.com>
Date: Tue, 19 Dec 2017 09:57:36 +0000
On 10/25/17 15:56, O'Connor, Daniel wrote:
>> On 26 Oct 2017, at 08:13, Colin Percival <cperciva_at_tarsnap.com> wrote:
>> [Proposal for removing hpt* drivers since hpt27xx and hptnr take a long
>> time to in DEVICE_PROBE.]
> 
> Seems sensible to me, but also worth contacting the blob authors if
> possible and asking them what gives (and if they can fix it).

Turns out that they were indeed able to fix it, with startling rapidity.
delphij_at_ committed r325683 (MFCed as r32600[56]) which reduces the time
spent in these DEVICE_PROBE routines from ~150 ms down to ~37 *us* on my
laptop.  So my immediate desire for faster booting has been satisfied with
regard to these drivers.

I know some people (CCed) were enthusiastic about removing these from GENERIC
on the basis that we shouldn't have binary blobs in GENERIC; while I'm
certainly sympathetic to this, I'd suggest that it should be done by someone
who has time to look at the other binary blobs in the tree and formulate a
general policy rather than just picking on the hpt* drivers.  Unfortunately,
that person is not me; I have 12 days left to submit a talk to AsiaBSDCon
about my work on profiling the kernel boot (which is how I noticed the slow
probing originally) and then a long list of other places to speed up the
boot performance.

-- 
Colin Percival
Security Officer Emeritus, FreeBSD | The power to serve
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid
Received on Tue Dec 19 2017 - 09:02:03 UTC

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