From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Balbir Singh <bsingharora@gmail.com>,
paulus@samba.org, mpe@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/mm: Use jump label to speed up radix_enabled check
Date: Wed, 27 Apr 2016 12:30:30 +0530 [thread overview]
Message-ID: <87mvofedtd.fsf@skywalker.in.ibm.com> (raw)
In-Reply-To: <1461721589.3586.0.camel@kernel.crashing.org>
Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:
> On Wed, 2016-04-27 at 11:00 +1000, Balbir Singh wrote:
>> Just basic testing across CPUs with various mm features=C2=A0
>> enabled/disabled. Just for sanity
>
> I still don't think it's worth scattering the change. Either the jump
> label works or it doesn't ... The only problem is make sure we identify
> all the pre-boot ones but that's about it.
>
There are two ways to do this. One is to follow the approach listed
below done by Kevin, which is to do the jump_label_init early during boot a=
nd
switch both cpu and mmu feature check to plain jump label.
http://mid.gmane.org/1440415228-8006-1-git-send-email-haokexin@gmail.com
I already found one use case of cpu_has_feature before that
jump_label_init. In this approach we need to carefully audit all the
cpu/mmu_has_feature calls to make sure they don't get called before
jump_label_init. A missed conversion mean we miss a cpu/mmu feature
check.
Other option is to follow the patch I posted above, with the simple
change of renaming mmu_feature_enabled to mmu_has_feature. So we can
use it in early boot without really worrying about when we init jump
label.
What do you suggest we follow ?
-aneesh
next prev parent reply other threads:[~2016-04-27 7:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-26 16:24 [PATCH] powerpc/mm: Use jump label to speed up radix_enabled check Aneesh Kumar K.V
2016-04-26 21:05 ` Benjamin Herrenschmidt
2016-04-26 22:16 ` Balbir Singh
2016-04-26 23:05 ` Benjamin Herrenschmidt
2016-04-27 1:00 ` Balbir Singh
2016-04-27 1:46 ` Benjamin Herrenschmidt
2016-04-27 7:00 ` Aneesh Kumar K.V [this message]
2016-04-27 9:30 ` Aneesh Kumar K.V
2016-06-09 4:12 ` Benjamin Herrenschmidt
2016-06-09 6:00 ` Aneesh Kumar K.V
2016-06-09 15:58 ` Aneesh Kumar K.V
2016-06-10 4:16 ` Michael Ellerman
2016-06-10 5:46 ` Benjamin Herrenschmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87mvofedtd.fsf@skywalker.in.ibm.com \
--to=aneesh.kumar@linux.vnet.ibm.com \
--cc=benh@kernel.crashing.org \
--cc=bsingharora@gmail.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.