From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0ED172C008A for ; Tue, 18 Jun 2013 10:17:48 +1000 (EST) Message-ID: <1371514650.21896.160.camel@pasglop> Subject: Re: [PATCH 1/2] powerpc: add Book E support to 64-bit hibernation From: Benjamin Herrenschmidt To: Scott Wood Date: Tue, 18 Jun 2013 10:17:30 +1000 In-Reply-To: <1371513683.9073.6@snotra> References: <1371513683.9073.6@snotra> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: Wood Scott-B07421 , "anton@enomsg.org" , Wang Dongsheng-B40534 , "johannes@sipsolutions.net" , "linuxppc-dev@lists.ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2013-06-17 at 19:01 -0500, Scott Wood wrote: > I really doubt the exception scratch registers need to be saved -- > we're not trying to restore into the middle of an exception > prolog/epilog. > > book3s has the PACA as well and they don't save it. Don't we rely on > things like boot-time memory allocations happening in the same place > when we resume? extlb is part of the PACA, so the same applies. I doubt we seriously tested hibernation :-) The PACA SPR should definitely be saved/restored. > Granted, this isn't performance critical so it may seem better to > save/restore just in case, but there's value in not unnecessarily > deviating from what book3s does. Cheers, Ben.