Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754807AbbGXSzA (ORCPT ); Fri, 24 Jul 2015 14:55:00 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:27926 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752941AbbGXSy6 (ORCPT ); Fri, 24 Jul 2015 14:54:58 -0400 Date: Fri, 24 Jul 2015 14:54:51 -0400 From: Konrad Rzeszutek Wilk To: David Vrabel Cc: xen-devel@lists.xenproject.org, Boris Ostrovsky , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Daniel Kiper Subject: Re: [PATCHv2 05/10] xen/balloon: rationalize memory hotplug stats Message-ID: <20150724185451.GC12824@l.oracle.com> References: <1437738468-24110-1-git-send-email-david.vrabel@citrix.com> <1437738468-24110-6-git-send-email-david.vrabel@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1437738468-24110-6-git-send-email-david.vrabel@citrix.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6324 Lines: 196 On Fri, Jul 24, 2015 at 12:47:43PM +0100, David Vrabel wrote: > The stats used for memory hotplug make no sense and are fiddled with > in odd ways. Remove them and introduce total_pages to track the total > number of pages (both populated and unpopulated) including those within > hotplugged regions (note that this includes not yet onlined pages). > > This will be used in the following commit when deciding whether s/the following commit/"xen/balloon: only hotplug additional memory if required" patch > additional memory needs to be hotplugged. > > Signed-off-by: David Vrabel > --- > drivers/xen/balloon.c | 75 +++++++++------------------------------------------ > include/xen/balloon.h | 5 +--- > 2 files changed, 13 insertions(+), 67 deletions(-) > > diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c > index 29aeb8f..b5037b1 100644 > --- a/drivers/xen/balloon.c > +++ b/drivers/xen/balloon.c > @@ -194,21 +194,6 @@ static enum bp_state update_schedule(enum bp_state state) > } > > #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG > -static long current_credit(void) > -{ > - return balloon_stats.target_pages - balloon_stats.current_pages - > - balloon_stats.hotplug_pages; > -} > - > -static bool balloon_is_inflated(void) > -{ > - if (balloon_stats.balloon_low || balloon_stats.balloon_high || > - balloon_stats.balloon_hotplug) > - return true; > - else > - return false; > -} > - > static struct resource *additional_memory_resource(phys_addr_t size) > { > struct resource *res; > @@ -300,10 +285,7 @@ static enum bp_state reserve_additional_memory(long credit) > goto err; > } > > - balloon_hotplug -= credit; > - > - balloon_stats.hotplug_pages += credit; > - balloon_stats.balloon_hotplug = balloon_hotplug; > + balloon_stats.total_pages += balloon_hotplug; > > return BP_DONE; > err: > @@ -319,11 +301,6 @@ static void xen_online_page(struct page *page) > > __balloon_append(page); > > - if (balloon_stats.hotplug_pages) > - --balloon_stats.hotplug_pages; > - else > - --balloon_stats.balloon_hotplug; > - > mutex_unlock(&balloon_mutex); > } > > @@ -340,32 +317,22 @@ static struct notifier_block xen_memory_nb = { > .priority = 0 > }; > #else > -static long current_credit(void) > +static enum bp_state reserve_additional_memory(long credit) > { > - unsigned long target = balloon_stats.target_pages; > - > - target = min(target, > - balloon_stats.current_pages + > - balloon_stats.balloon_low + > - balloon_stats.balloon_high); > - > - return target - balloon_stats.current_pages; > + balloon_stats.target_pages = balloon_stats.current_pages; > + return BP_DONE; > } > +#endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */ > > -static bool balloon_is_inflated(void) > +static long current_credit(void) > { > - if (balloon_stats.balloon_low || balloon_stats.balloon_high) > - return true; > - else > - return false; > + return balloon_stats.target_pages - balloon_stats.current_pages; > } > > -static enum bp_state reserve_additional_memory(long credit) > +static bool balloon_is_inflated(void) > { > - balloon_stats.target_pages = balloon_stats.current_pages; > - return BP_DONE; > + return balloon_stats.balloon_low || balloon_stats.balloon_high; > } > -#endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */ > > static enum bp_state increase_reservation(unsigned long nr_pages) > { > @@ -378,15 +345,6 @@ static enum bp_state increase_reservation(unsigned long nr_pages) > .domid = DOMID_SELF > }; > > -#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG > - if (!balloon_stats.balloon_low && !balloon_stats.balloon_high) { > - nr_pages = min(nr_pages, balloon_stats.balloon_hotplug); > - balloon_stats.hotplug_pages += nr_pages; > - balloon_stats.balloon_hotplug -= nr_pages; > - return BP_DONE; > - } > -#endif > - > if (nr_pages > ARRAY_SIZE(frame_list)) > nr_pages = ARRAY_SIZE(frame_list); > > @@ -449,15 +407,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) > .domid = DOMID_SELF > }; > > -#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG > - if (balloon_stats.hotplug_pages) { > - nr_pages = min(nr_pages, balloon_stats.hotplug_pages); > - balloon_stats.hotplug_pages -= nr_pages; > - balloon_stats.balloon_hotplug += nr_pages; > - return BP_DONE; > - } > -#endif > - > if (nr_pages > ARRAY_SIZE(frame_list)) > nr_pages = ARRAY_SIZE(frame_list); > > @@ -647,6 +596,8 @@ static void __init balloon_add_region(unsigned long start_pfn, > don't subtract from it. */ > __balloon_append(page); > } > + > + balloon_stats.total_pages += extra_pfn_end - start_pfn; > } > > static int __init balloon_init(void) > @@ -664,6 +615,7 @@ static int __init balloon_init(void) > balloon_stats.target_pages = balloon_stats.current_pages; > balloon_stats.balloon_low = 0; > balloon_stats.balloon_high = 0; > + balloon_stats.total_pages = balloon_stats.current_pages; > > balloon_stats.schedule_delay = 1; > balloon_stats.max_schedule_delay = 32; > @@ -671,9 +623,6 @@ static int __init balloon_init(void) > balloon_stats.max_retry_count = RETRY_UNLIMITED; > > #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG > - balloon_stats.hotplug_pages = 0; > - balloon_stats.balloon_hotplug = 0; > - > set_online_page_callback(&xen_online_page); > register_memory_notifier(&xen_memory_nb); > #endif > diff --git a/include/xen/balloon.h b/include/xen/balloon.h > index cc2e1a7..c8aee7a 100644 > --- a/include/xen/balloon.h > +++ b/include/xen/balloon.h > @@ -11,14 +11,11 @@ struct balloon_stats { > /* Number of pages in high- and low-memory balloons. */ > unsigned long balloon_low; > unsigned long balloon_high; > + unsigned long total_pages; > unsigned long schedule_delay; > unsigned long max_schedule_delay; > unsigned long retry_count; > unsigned long max_retry_count; > -#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG > - unsigned long hotplug_pages; > - unsigned long balloon_hotplug; > -#endif > }; > > extern struct balloon_stats balloon_stats; > -- > 2.1.4 > -- 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/