From 7659f5d6448095ef436891c33bdd7c8500620a00 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 31 Oct 2019 15:29:27 +0100 Subject: [PATCH] powerpc/pseries/cmm: Rip out memory isolate notifier The memory isolate notifier was added to allow to offline memory blocks that contain inflated/"loaned" pages. We can achieve the same using the balloon compaction framework. Get rid of the memory isolate notifier. Also, we can get rid of cmm_mem_going_offline(), as we will never reach that code path now when we have allocated memory in the balloon (allocated pages are unmovable and will no longer be special-cased using the memory isolation notifier). Leave the memory notifier in place, so we can still back off in case memory gets offlined. Signed-off-by: David Hildenbrand Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191031142933.10779-7-david@redhat.com --- arch/powerpc/platforms/pseries/cmm.c | 97 +----------------------------------- 1 file changed, 1 insertion(+), 96 deletions(-) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index f82c468ca2c4..29416b621189 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -38,12 +38,8 @@ #define CMM_MIN_MEM_MB 256 #define KB2PAGES(_p) ((_p)>>(PAGE_SHIFT-10)) #define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10)) -/* - * The priority level tries to ensure that this notifier is called as - * late as possible to reduce thrashing in the shared memory pool. - */ + #define CMM_MEM_HOTPLUG_PRI 1 -#define CMM_MEM_ISOLATE_PRI 15 static unsigned int delay = CMM_DEFAULT_DELAY; static unsigned int hotplug_delay = CMM_HOTPLUG_DELAY; @@ -447,90 +443,6 @@ static struct notifier_block cmm_reboot_nb = { }; /** - * cmm_count_pages - Count the number of pages loaned in a particular range. - * - * @arg: memory_isolate_notify structure with address range and count - * - * Return value: - * 0 on success - **/ -static unsigned long cmm_count_pages(void *arg) -{ - struct memory_isolate_notify *marg = arg; - struct page *page; - - spin_lock(&cmm_lock); - list_for_each_entry(page, &cmm_page_list, lru) { - if (page_to_pfn(page) >= marg->start_pfn && - page_to_pfn(page) < marg->start_pfn + marg->nr_pages) - marg->pages_found++; - } - spin_unlock(&cmm_lock); - return 0; -} - -/** - * cmm_memory_isolate_cb - Handle memory isolation notifier calls - * @self: notifier block struct - * @action: action to take - * @arg: struct memory_isolate_notify data for handler - * - * Return value: - * NOTIFY_OK or notifier error based on subfunction return value - **/ -static int cmm_memory_isolate_cb(struct notifier_block *self, - unsigned long action, void *arg) -{ - int ret = 0; - - if (action == MEM_ISOLATE_COUNT) - ret = cmm_count_pages(arg); - - return notifier_from_errno(ret); -} - -static struct notifier_block cmm_mem_isolate_nb = { - .notifier_call = cmm_memory_isolate_cb, - .priority = CMM_MEM_ISOLATE_PRI -}; - -/** - * cmm_mem_going_offline - Unloan pages where memory is to be removed - * @arg: memory_notify structure with page range to be offlined - * - * Return value: - * 0 on success - **/ -static int cmm_mem_going_offline(void *arg) -{ - struct memory_notify *marg = arg; - struct page *page, *tmp; - unsigned long freed = 0; - - cmm_dbg("Memory going offline, searching PFN 0x%lx (%ld pages).\n", - marg->start_pfn, marg->nr_pages); - spin_lock(&cmm_lock); - - /* Search the page list for pages in the range to be offlined */ - list_for_each_entry_safe(page, tmp, &cmm_page_list, lru) { - if (page_to_pfn(page) < marg->start_pfn || - page_to_pfn(page) >= marg->start_pfn + marg->nr_pages) - continue; - plpar_page_set_active(page); - list_del(&page->lru); - adjust_managed_page_count(page, 1); - __free_page(page); - freed++; - loaned_pages--; - } - - spin_unlock(&cmm_lock); - cmm_dbg("Released %ld pages in the search range.\n", freed); - - return 0; -} - -/** * cmm_memory_cb - Handle memory hotplug notifier calls * @self: notifier block struct * @action: action to take @@ -549,7 +461,6 @@ static int cmm_memory_cb(struct notifier_block *self, case MEM_GOING_OFFLINE: mutex_lock(&hotplug_mutex); hotplug_occurred = 1; - ret = cmm_mem_going_offline(arg); break; case MEM_OFFLINE: case MEM_CANCEL_OFFLINE: @@ -596,10 +507,6 @@ static int cmm_init(void) if (rc) goto out_unregister_notifier; - rc = register_memory_isolate_notifier(&cmm_mem_isolate_nb); - if (rc) - goto out_unregister_notifier; - if (cmm_disabled) return 0; @@ -612,7 +519,6 @@ static int cmm_init(void) return 0; out_unregister_notifier: unregister_memory_notifier(&cmm_mem_nb); - unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); cmm_unregister_sysfs(&cmm_dev); out_reboot_notifier: unregister_reboot_notifier(&cmm_reboot_nb); @@ -634,7 +540,6 @@ static void cmm_exit(void) unregister_oom_notifier(&cmm_oom_nb); unregister_reboot_notifier(&cmm_reboot_nb); unregister_memory_notifier(&cmm_mem_nb); - unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); cmm_free_pages(loaned_pages); cmm_unregister_sysfs(&cmm_dev); } -- 2.11.0