lkml.org 
[lkml]   [2018]   [May]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 08/15] powerpc/powernv: implement opal_put_chars_atomic
Date
Nicholas Piggin <npiggin@gmail.com> writes:

> On Tue, 01 May 2018 19:48:58 +1000
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
>
>> On Tue, 2018-05-01 at 00:55 +1000, Nicholas Piggin wrote:
>> > The RAW console does not need writes to be atomic, so relax
>> > opal_put_chars to be able to do partial writes, and implement an
>> > _atomic variant which does not take a spinlock. This API is used
>> > in xmon, so the less locking that is used, the better chance there
>> > is that a crash can be debugged.
>>
>> Same comment I already had :-) "atomic" in Linux tends to mean
>> something else (ie, atomic context), so I'd rather have something
>> like opal_put_chars_sync() or such...
>
> Oh yeah, I didn't ignore you, just... I thought atomic was okay.
> atomic *also* tends to mean happens atomically. I think the in
> atomic context meaning actually tends to be inatomic.
>
> Sync I actually thought could be more easily confused with
> synchronous vs asynchronous here.

I think we probably want opal_put_chars() to stay as it is.

And then add a variant for the call (just xmon?) that want lock free
behaviour.

opal_put_chars_unlocked() or something?

cheers

\
 
 \ /
  Last update: 2018-05-07 12:36    [W:0.080 / U:2.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site