From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH 2/4] build: Alloc space for sched list in the link file Date: Fri, 18 Dec 2015 17:23:27 +0000 Message-ID: <5674410F.3080505@citrix.com> References: <1450385974-12732-1-git-send-email-jonathan.creekmore@gmail.com> <1450385974-12732-3-git-send-email-jonathan.creekmore@gmail.com> <5673CB60.2050703@citrix.com> <567438F2.1030406@citrix.com> <56744B6B02000078000C16D9@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1a9yke-0003OG-Tu for xen-devel@lists.xenproject.org; Fri, 18 Dec 2015 17:23:33 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jonathan Creekmore , Jan Beulich Cc: xen-devel@lists.xenproject.org, Keir Fraser , Stefano Stabellini , Ian Campbell List-Id: xen-devel@lists.xenproject.org On 18/12/15 17:11, Jonathan Creekmore wrote: >> On Dec 18, 2015, at 11:07 AM, Jan Beulich wrote: >> >>>>> On 18.12.15 at 17:48, wrote: >>> On 18/12/15 16:40, Jonathan Creekmore wrote: >>>>> On Dec 18, 2015, at 3:01 AM, Andrew Cooper wrote: >>>>> >>>>> On 17/12/2015 20:59, Jonathan Creekmore wrote: >>>>>> Creates a section to contain scheduler entry pointers that are gathered >>>>>> together into an array. This will allow, in a follow-on patch, scheduler >>>>>> entries to be automatically gathered together into the array for >>>>>> automatic parsing. >>>>>> >>>>>> CC: Ian Campbell >>>>>> CC: Stefano Stabellini >>>>>> CC: Keir Fraser >>>>>> CC: Jan Beulich >>>>>> CC: Andrew Cooper >>>>>> Signed-off-by: Jonathan Creekmore >>>>>> --- >>>>>> xen/arch/arm/xen.lds.S | 4 ++++ >>>>>> xen/arch/x86/xen.lds.S | 4 ++++ >>>>>> 2 files changed, 8 insertions(+) >>>>>> >>>>>> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S >>>>>> index 0488f37..39a4c86 100644 >>>>>> --- a/xen/arch/arm/xen.lds.S >>>>>> +++ b/xen/arch/arm/xen.lds.S >>>>>> @@ -57,6 +57,10 @@ SECTIONS >>>>>> . = ALIGN(PAGE_SIZE); >>>>>> *(.data.page_aligned) >>>>>> *(.data) >>>>>> + . = ALIGN(8); >>>>>> + __schedulers_start = .; >>>>>> + *(.data.schedulers) >>>>>> + __schedulers_end = .; >>>>> These arrays are only ever used in __init scheduler_init(). They should >>>>> be in .init.data rather than .data, which allows their memory to be >>>>> reclaimed after boot. >>>>> >>>>> With that, Reviewed-by: Andrew Cooper >>>> So, they are used in scheduler_init() which is marked __init, but >>> scheduler_alloc >>>> also uses that array (and did before my patch) and it is not marked __init. >>> Ah yes - so they are. Apologies for the noise. This should be in .data >>> and my R-b stands. >> In .rodata perhaps? > I initially put it in .rodata, but the current algorithm for choosing the scheduler NULLs out > the pointers in the array if the global_init() function fails. To emulate that behavior, I had to > move the section to .data instead of .rodata. Hmm. That is unfortunate. Best to leave it in .data, and leave fixing the scheduler initialisation to the other scheduler clean-up work; there is plenty of other cleanup work to do, and conflating the two issues is best avoided. ~Andrew