From: Andi Kleen <andi@firstfloor.org>
To: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: tony.luck@intel.com, andi@firstfloor.org, bp@amd64.org,
gong.chen@linux.intel.com, ananth@in.ibm.com,
masbock@linux.vnet.ibm.com, x86@kernel.org,
linux-kernel@vger.kernel.org, lcm@us.ibm.com, mingo@redhat.com,
tglx@linutronix.de, linux-edac@vger.kernel.org
Subject: Re: [PATCH 1/2] x86/mce: Pack boolean MCE boot flags into a structure
Date: Mon, 27 Aug 2012 15:58:59 +0200 [thread overview]
Message-ID: <20120827135859.GY16230@one.firstfloor.org> (raw)
In-Reply-To: <20120827112503.10313.62594.stgit@localhost.localdomain>
On Mon, Aug 27, 2012 at 04:55:03PM +0530, Naveen N. Rao wrote:
> Many MCE boot flags are boolean in nature, but are declared as integers
> currently. We can pack these into a bitfield to save some space.
Note that this doesn't necessarily save anything because it needs more
code to access, and accesses are more common than the flag
cmpl $0,foo(%rip) 7 bytes
testl $1,foo(%rip) 10 bytes
bt $0,foo(%rip) 8 bytes
Even worse for writes. The best you can usually do is to use chars on
x86.
-Andi
next prev parent reply other threads:[~2012-08-27 13:59 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-27 11:25 Naveen N. Rao
2012-08-27 11:25 ` [PATCH 2/2] x86/mce: Honour bios-set CMCI threshold Naveen N. Rao
2012-08-27 14:48 ` Borislav Petkov
2012-08-27 15:11 ` Naveen N. Rao
2012-08-27 15:21 ` Borislav Petkov
2012-08-27 13:58 ` Andi Kleen [this message]
2012-08-27 14:18 ` [PATCH 1/2] x86/mce: Pack boolean MCE boot flags into a structure Borislav Petkov
2012-08-28 6:55 ` Naveen N. Rao
2012-08-27 14:36 ` Borislav Petkov
2012-08-27 15:35 ` Naveen N. Rao
2012-08-27 15:47 ` Borislav Petkov
2012-08-27 16:01 ` Naveen N. Rao
2012-08-27 16:34 ` Borislav Petkov
2012-08-27 17:14 ` Naveen N. Rao
2012-08-27 20:18 ` Borislav Petkov
2012-08-28 7:17 ` Naveen N. Rao
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