All of lore.kernel.org
 help / color / mirror / Atom feed
From: Segher Boessenkool <segher@kernel.crashing.org>
To: michael@ellerman.id.au
Cc: Olof Johansson <olof@lixom.net>,
	linuxppc-dev@ozlabs.org, paulus@samba.org, anton@samba.org
Subject: Re: [PATCH] powerpc: save trap number in bad_stack
Date: Fri, 20 Apr 2007 10:51:06 +0200	[thread overview]
Message-ID: <a3519d3b3474ab6530e6e1092e3d60d0@kernel.crashing.org> (raw)
In-Reply-To: <1177035524.6890.7.camel@concordia.ozlabs.ibm.com>

>>> +	u64 trap_save;			/* Used when bad stack is encountered */
>>
>> Can you put it elsewhere in the PACA (around less frequently used
>> bits) ? This is a pretty hot area of the PACA...
>
> It's only set in the bad_stack case though.
>
> You should put it after cpu_start, there's a bit hole there, and
> trap_save is readonly during normal operation, so it shouldn't be a
> performance hit.

That's not a performance hit compared to the current
state of the code, sure; but that "hot slot" could
be used for a hotter variable, instead.


Segher

  reply	other threads:[~2007-04-20  8:51 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-16  6:23 [PATCH] powerpc: save trap number in bad_stack Olof Johansson
2007-04-19 23:17 ` Benjamin Herrenschmidt
2007-04-20  2:18   ` Michael Ellerman
2007-04-20  8:51     ` Segher Boessenkool [this message]
2007-04-22 23:34   ` Olof Johansson
2007-04-22 23:38 ` [PATCH] [v2] " Olof Johansson
2007-04-23  9:29   ` Gabriel Paubert
2007-04-23 11:49     ` Olof Johansson
2007-04-23 12:19   ` [PATCH] [v3] " Olof Johansson
2007-04-23 15:11     ` [PATCH] [v4] " Olof Johansson
2007-04-23 15:34       ` Stephen Rothwell
2007-04-23 13:22   ` [PATCH] [v2] " Stephen Rothwell
2007-04-23 13:33     ` Michael Ellerman
2007-04-23 13:39     ` David Gibson
2007-04-23 13:54     ` Olof Johansson

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=a3519d3b3474ab6530e6e1092e3d60d0@kernel.crashing.org \
    --to=segher@kernel.crashing.org \
    --cc=anton@samba.org \
    --cc=linuxppc-dev@ozlabs.org \
    --cc=michael@ellerman.id.au \
    --cc=olof@lixom.net \
    --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.