From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-in-08.arcor-online.net (mail-in-08.arcor-online.net [151.189.21.48]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.arcor.de", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 2125DDDE2D for ; Fri, 20 Apr 2007 18:51:12 +1000 (EST) In-Reply-To: <1177035524.6890.7.camel@concordia.ozlabs.ibm.com> References: <20070416062347.GA20196@lixom.net> <1177024678.7286.23.camel@localhost.localdomain> <1177035524.6890.7.camel@concordia.ozlabs.ibm.com> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: From: Segher Boessenkool Subject: Re: [PATCH] powerpc: save trap number in bad_stack Date: Fri, 20 Apr 2007 10:51:06 +0200 To: michael@ellerman.id.au Cc: Olof Johansson , linuxppc-dev@ozlabs.org, paulus@samba.org, anton@samba.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >>> + 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