From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752500AbbCWO5w (ORCPT ); Mon, 23 Mar 2015 10:57:52 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:51455 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752100AbbCWO5v (ORCPT ); Mon, 23 Mar 2015 10:57:51 -0400 X-IronPort-AV: E=Sophos;i="5.11,452,1422921600"; d="scan'208";a="247486844" Message-ID: <551029D3.7090306@citrix.com> Date: Mon, 23 Mar 2015 14:57:23 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: Juergen Gross , David Vrabel , , , , , , Subject: Re: [Xen-devel] [Patch V2 1/2] xen: prepare p2m list for memory hotplug References: <1426856139-3359-1-git-send-email-jgross@suse.com> <1426856139-3359-2-git-send-email-jgross@suse.com> <55100B21.6040605@citrix.com> <5510233C.4080004@suse.com> In-Reply-To: <5510233C.4080004@suse.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23/03/15 14:29, Juergen Gross wrote: > On 03/23/2015 01:46 PM, David Vrabel wrote: >> On 20/03/15 12:55, Juergen Gross wrote: >>> Commit 054954eb051f35e74b75a566a96fe756015352c8 ("xen: switch to linear >>> virtual mapped sparse p2m list") introduced a regression regarding to >>> memory hotplug for a pv-domain: as the virtual space for the p2m list >>> is allocated for the to be expected memory size of the domain only, >>> hotplugged memory above that size will not be usable by the domain. >>> >>> Correct this by using a configurable size for the p2m list in case of >>> memory hotplug enabled (default supported memory size is 512 GB for >>> 64 bit domains and 4 GB for 32 bit domains). >>> >>> Signed-off-by: Juergen Gross >>> --- >>> arch/x86/xen/p2m.c | 10 +++++++++- >>> drivers/xen/Kconfig | 14 ++++++++++++++ >>> 2 files changed, 23 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c >>> index 9f93af5..b47124d 100644 >>> --- a/arch/x86/xen/p2m.c >>> +++ b/arch/x86/xen/p2m.c >>> @@ -91,6 +91,12 @@ EXPORT_SYMBOL_GPL(xen_p2m_size); >>> unsigned long xen_max_p2m_pfn __read_mostly; >>> EXPORT_SYMBOL_GPL(xen_max_p2m_pfn); >>> >>> +#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT >>> +#define P2M_LIMIT CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT >>> +#else >>> +#define P2M_LIMIT 0 >>> +#endif >>> + >>> static DEFINE_SPINLOCK(p2m_update_lock); >>> >>> static unsigned long *p2m_mid_missing_mfn; >>> @@ -385,9 +391,11 @@ static void __init xen_rebuild_p2m_list(unsigned >>> long *p2m) >>> void __init xen_vmalloc_p2m_tree(void) >>> { >>> static struct vm_struct vm; >>> + unsigned long p2m_limit; >>> >>> + p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / >>> PAGE_SIZE; >>> vm.flags = VM_ALLOC; >>> - vm.size = ALIGN(sizeof(unsigned long) * xen_max_p2m_pfn, >>> + vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, >>> p2m_limit), >>> PMD_SIZE * PMDS_PER_MID_PAGE); >>> vm_area_register_early(&vm, PMD_SIZE * PMDS_PER_MID_PAGE); >>> pr_notice("p2m virtual area at %p, size is %lx\n", vm.addr, >>> vm.size); >>> diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig >>> index b812462..0f1b509 100644 >>> --- a/drivers/xen/Kconfig >>> +++ b/drivers/xen/Kconfig >>> @@ -55,6 +55,20 @@ config XEN_BALLOON_MEMORY_HOTPLUG >>> >>> In that case step 3 should be omitted. >>> >>> +config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT >>> + int >> >> Because you've not supplied a summary for this option, it is not user >> configurable. Is this intentional? > > No. Sorry, I just tested it via editing .config, not using the menues. > Can you add it when committing (e.g. "Upper limit in GBs a pv domain > can be expanded to using memory hotplug")? > > Or should I send another patch? I'll fix it up. David