From 4a1745c5bf92232f115e28296475dc42254b1c7d Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 31 Oct 2019 15:29:25 +0100 Subject: [PATCH] powerpc/pseries/cmm: Drop page array We can simply store the pages in a list (page->lru), no need for a separate data structure (+ complicated handling). This is how most other balloon drivers store allocated pages without additional tracking data. For the notifiers, use page_to_pfn() to check if a page is in the applicable range. Use page_to_phys() in plpar_page_set_loaned() and plpar_page_set_active() (I assume due to the __pa() that's the right thing to do). Signed-off-by: David Hildenbrand Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191031142933.10779-5-david@redhat.com --- arch/powerpc/platforms/pseries/cmm.c | 163 ++++++--------------------- 1 file changed, 36 insertions(+), 127 deletions(-) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 738eb1681d40..33d31e48ec15 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -75,21 +75,13 @@ module_param_named(debug, cmm_debug, uint, 0644); MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. " "[Default=" __stringify(CMM_DEBUG) "]"); -#define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long)) - #define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); } -struct cmm_page_array { - struct cmm_page_array *next; - unsigned long index; - unsigned long page[CMM_NR_PAGES]; -}; - static unsigned long loaned_pages; static unsigned long loaned_pages_target; static unsigned long oom_freed_pages; -static struct cmm_page_array *cmm_page_list; +static LIST_HEAD(cmm_page_list); static DEFINE_SPINLOCK(cmm_lock); static DEFINE_MUTEX(hotplug_mutex); @@ -97,8 +89,9 @@ static int hotplug_occurred; /* protected by the hotplug mutex */ static struct task_struct *cmm_thread_ptr; -static long plpar_page_set_loaned(unsigned long vpa) +static long plpar_page_set_loaned(struct page *page) { + const unsigned long vpa = page_to_phys(page); unsigned long cmo_page_sz = cmo_get_page_size(); long rc = 0; int i; @@ -113,8 +106,9 @@ static long plpar_page_set_loaned(unsigned long vpa) return rc; } -static long plpar_page_set_active(unsigned long vpa) +static long plpar_page_set_active(struct page *page) { + const unsigned long vpa = page_to_phys(page); unsigned long cmo_page_sz = cmo_get_page_size(); long rc = 0; int i; @@ -138,8 +132,7 @@ static long plpar_page_set_active(unsigned long vpa) **/ static long cmm_alloc_pages(long nr) { - struct cmm_page_array *pa, *npa; - unsigned long addr; + struct page *page; long rc; cmm_dbg("Begin request for %ld pages\n", nr); @@ -156,43 +149,20 @@ static long cmm_alloc_pages(long nr) break; } - addr = __get_free_page(GFP_NOIO | __GFP_NOWARN | - __GFP_NORETRY | __GFP_NOMEMALLOC); - if (!addr) + page = alloc_page(GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | + __GFP_NOMEMALLOC); + if (!page) break; spin_lock(&cmm_lock); - pa = cmm_page_list; - if (!pa || pa->index >= CMM_NR_PAGES) { - /* Need a new page for the page list. */ - spin_unlock(&cmm_lock); - npa = (struct cmm_page_array *)__get_free_page( - GFP_NOIO | __GFP_NOWARN | - __GFP_NORETRY | __GFP_NOMEMALLOC); - if (!npa) { - pr_info("%s: Can not allocate new page list\n", __func__); - free_page(addr); - break; - } - spin_lock(&cmm_lock); - pa = cmm_page_list; - - if (!pa || pa->index >= CMM_NR_PAGES) { - npa->next = pa; - npa->index = 0; - pa = npa; - cmm_page_list = pa; - } else - free_page((unsigned long) npa); - } - - if ((rc = plpar_page_set_loaned(__pa(addr)))) { + rc = plpar_page_set_loaned(page); + if (rc) { pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc); spin_unlock(&cmm_lock); - free_page(addr); + __free_page(page); break; } - pa->page[pa->index++] = addr; + list_add(&page->lru, &cmm_page_list); loaned_pages++; totalram_pages_dec(); spin_unlock(&cmm_lock); @@ -212,25 +182,16 @@ static long cmm_alloc_pages(long nr) **/ static long cmm_free_pages(long nr) { - struct cmm_page_array *pa; - unsigned long addr; + struct page *page, *tmp; cmm_dbg("Begin free of %ld pages.\n", nr); spin_lock(&cmm_lock); - pa = cmm_page_list; - while (nr) { - if (!pa || pa->index <= 0) + list_for_each_entry_safe(page, tmp, &cmm_page_list, lru) { + if (!nr) break; - addr = pa->page[--pa->index]; - - if (pa->index == 0) { - pa = pa->next; - free_page((unsigned long) cmm_page_list); - cmm_page_list = pa; - } - - plpar_page_set_active(__pa(addr)); - free_page(addr); + plpar_page_set_active(page); + list_del(&page->lru); + __free_page(page); loaned_pages--; nr--; totalram_pages_inc(); @@ -496,20 +457,13 @@ static struct notifier_block cmm_reboot_nb = { static unsigned long cmm_count_pages(void *arg) { struct memory_isolate_notify *marg = arg; - struct cmm_page_array *pa; - unsigned long start = (unsigned long)pfn_to_kaddr(marg->start_pfn); - unsigned long end = start + (marg->nr_pages << PAGE_SHIFT); - unsigned long idx; + struct page *page; spin_lock(&cmm_lock); - pa = cmm_page_list; - while (pa) { - if ((unsigned long)pa >= start && (unsigned long)pa < end) + 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++; - for (idx = 0; idx < pa->index; idx++) - if (pa->page[idx] >= start && pa->page[idx] < end) - marg->pages_found++; - pa = pa->next; } spin_unlock(&cmm_lock); return 0; @@ -550,69 +504,24 @@ static struct notifier_block cmm_mem_isolate_nb = { static int cmm_mem_going_offline(void *arg) { struct memory_notify *marg = arg; - unsigned long start_page = (unsigned long)pfn_to_kaddr(marg->start_pfn); - unsigned long end_page = start_page + (marg->nr_pages << PAGE_SHIFT); - struct cmm_page_array *pa_curr, *pa_last, *npa; - unsigned long idx; + struct page *page, *tmp; unsigned long freed = 0; - cmm_dbg("Memory going offline, searching 0x%lx (%ld pages).\n", - start_page, marg->nr_pages); + 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 */ - pa_last = pa_curr = cmm_page_list; - while (pa_curr) { - for (idx = (pa_curr->index - 1); (idx + 1) > 0; idx--) { - if ((pa_curr->page[idx] < start_page) || - (pa_curr->page[idx] >= end_page)) - continue; - - plpar_page_set_active(__pa(pa_curr->page[idx])); - free_page(pa_curr->page[idx]); - freed++; - loaned_pages--; - totalram_pages_inc(); - pa_curr->page[idx] = pa_last->page[--pa_last->index]; - if (pa_last->index == 0) { - if (pa_curr == pa_last) - pa_curr = pa_last->next; - pa_last = pa_last->next; - free_page((unsigned long)cmm_page_list); - cmm_page_list = pa_last; - } - } - pa_curr = pa_curr->next; - } - - /* Search for page list structures in the range to be offlined */ - pa_last = NULL; - pa_curr = cmm_page_list; - while (pa_curr) { - if (((unsigned long)pa_curr >= start_page) && - ((unsigned long)pa_curr < end_page)) { - npa = (struct cmm_page_array *)__get_free_page( - GFP_NOIO | __GFP_NOWARN | - __GFP_NORETRY | __GFP_NOMEMALLOC); - if (!npa) { - spin_unlock(&cmm_lock); - cmm_dbg("Failed to allocate memory for list " - "management. Memory hotplug " - "failed.\n"); - return -ENOMEM; - } - memcpy(npa, pa_curr, PAGE_SIZE); - if (pa_curr == cmm_page_list) - cmm_page_list = npa; - if (pa_last) - pa_last->next = npa; - free_page((unsigned long) pa_curr); - freed++; - pa_curr = npa; - } - - pa_last = pa_curr; - pa_curr = pa_curr->next; + 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); + __free_page(page); + freed++; + loaned_pages--; + totalram_pages_inc(); } spin_unlock(&cmm_lock); -- 2.30.2