From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754460AbbCSRB2 (ORCPT ); Thu, 19 Mar 2015 13:01:28 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57713 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751157AbbCSRBZ (ORCPT ); Thu, 19 Mar 2015 13:01:25 -0400 Message-ID: <550B00E2.1060103@suse.com> Date: Thu, 19 Mar 2015 18:01:22 +0100 From: Juergen Gross User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Boris Ostrovsky , linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, daniel.kiper@oracle.com Subject: Re: [PATCH 1/2] xen: prepare p2m list for memory hotplug References: <1426775462-981-1-git-send-email-jgross@suse.com> <1426775462-981-2-git-send-email-jgross@suse.com> <550AF0FB.7000801@oracle.com> In-Reply-To: <550AF0FB.7000801@oracle.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/19/2015 04:53 PM, Boris Ostrovsky wrote: > On 03/19/2015 10:31 AM, 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 | 13 ++++++++++++- >> drivers/xen/Kconfig | 13 +++++++++++++ >> 2 files changed, 25 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c >> index 9f93af5..30e84ae 100644 >> --- a/arch/x86/xen/p2m.c >> +++ b/arch/x86/xen/p2m.c >> @@ -91,6 +91,17 @@ 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 >> +#ifdef CONFIG_X86_32 >> +BUILD_BUG_ON_MSG(CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT > 64) > > Will this work in Kconfig instead? > > range 0 64 if CONFIG_X86_32 I'll give it a try. Juergen > > -boris > >> +#endif >> +#define P2M_LIMIT max(xen_max_p2m_pfn, \ >> + ((unsigned long)((u64)CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT * \ >> + 1024 * 1024 * 1024 / PAGE_SIZE))) >> +#else >> +#define P2M_LIMIT xen_max_p2m_pfn >> +#endif >> + >> static DEFINE_SPINLOCK(p2m_update_lock); >> static unsigned long *p2m_mid_missing_mfn; >> @@ -387,7 +398,7 @@ void __init xen_vmalloc_p2m_tree(void) >> static struct vm_struct vm; >> vm.flags = VM_ALLOC; >> - vm.size = ALIGN(sizeof(unsigned long) * xen_max_p2m_pfn, >> + vm.size = ALIGN(sizeof(unsigned long) * 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..0a61ddf 100644 >> --- a/drivers/xen/Kconfig >> +++ b/drivers/xen/Kconfig >> @@ -55,6 +55,19 @@ config XEN_BALLOON_MEMORY_HOTPLUG >> In that case step 3 should be omitted. >> +config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT >> + int >> + default 512 if X86_64 >> + default 4 if X86_32 >> + depends on XEN_HAVE_PVMMU >> + depends on XEN_BALLOON_MEMORY_HOTPLUG >> + help >> + Upper limit in GBs a pv domain can be expanded to using memory >> + hotplug. >> + >> + This value is used to allocate enough space in internal tables >> needed >> + for physical memory administration. >> + >> config XEN_SCRUB_PAGES >> bool "Scrub pages before returning them to system" >> depends on XEN_BALLOON > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > >