x86, cpa: remove cpa pool code

Interrupt context no longer splits large page in cpa(). So we can do away
with cpa memory pool code.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 5 insertions, 155 deletions

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 44ccb028c350..74780800e7e7 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -1051,7 +1051,6 @@ void __init mem_init(void)
         if (boot_cpu_data.wp_works_ok < 0)
                 test_wp_bit();
 
-        cpa_init();
         save_pg_dir();
         zap_low_mappings();
 }
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 9d7587ac1ebc..f54a4d97530f 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -889,8 +889,6 @@ void __init mem_init(void)
                 reservedpages << (PAGE_SHIFT-10),
                 datasize >> 10,
                 initsize >> 10);
-
-        cpa_init();
 }
 
 void free_init_pages(char *what, unsigned long begin, unsigned long end)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 162812b05d28..f5e8663c0f75 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -447,114 +447,17 @@ out_unlock:
         return do_split;
 }
 
-static LIST_HEAD(page_pool);
-static unsigned long pool_size, pool_pages, pool_low;
-static unsigned long pool_used, pool_failed;
-
-static void cpa_fill_pool(struct page **ret)
-{
-        gfp_t gfp = GFP_KERNEL;
-        unsigned long flags;
-        struct page *p;
-
-        /*
-         * Avoid recursion (on debug-pagealloc) and also signal
-         * our priority to get to these pagetables:
-         */
-        if (current->flags & PF_MEMALLOC)
-                return;
-        current->flags |= PF_MEMALLOC;
-
-        /*
-         * Allocate atomically from atomic contexts:
-         */
-        if (in_atomic() || irqs_disabled() || debug_pagealloc)
-                gfp =  GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
-
-        while (pool_pages < pool_size || (ret && !*ret)) {
-                p = alloc_pages(gfp, 0);
-                if (!p) {
-                        pool_failed++;
-                        break;
-                }
-                /*
-                 * If the call site needs a page right now, provide it:
-                 */
-                if (ret && !*ret) {
-                        *ret = p;
-                        continue;
-                }
-                spin_lock_irqsave(&pgd_lock, flags);
-                list_add(&p->lru, &page_pool);
-                pool_pages++;
-                spin_unlock_irqrestore(&pgd_lock, flags);
-        }
-
-        current->flags &= ~PF_MEMALLOC;
-}
-
-#define SHIFT_MB                (20 - PAGE_SHIFT)
-#define ROUND_MB_GB             ((1 << 10) - 1)
-#define SHIFT_MB_GB             10
-#define POOL_PAGES_PER_GB       16
-
-void __init cpa_init(void)
-{
-        struct sysinfo si;
-        unsigned long gb;
-
-        si_meminfo(&si);
-        /*
-         * Calculate the number of pool pages:
-         *
-         * Convert totalram (nr of pages) to MiB and round to the next
-         * GiB. Shift MiB to Gib and multiply the result by
-         * POOL_PAGES_PER_GB:
-         */
-        if (debug_pagealloc) {
-                gb = ((si.totalram >> SHIFT_MB) + ROUND_MB_GB) >> SHIFT_MB_GB;
-                pool_size = POOL_PAGES_PER_GB * gb;
-        } else {
-                pool_size = 1;
-        }
-        pool_low = pool_size;
-
-        cpa_fill_pool(NULL);
-        printk(KERN_DEBUG
-               "CPA: page pool initialized %lu of %lu pages preallocated\n",
-               pool_pages, pool_size);
-}
-
 static int split_large_page(pte_t *kpte, unsigned long address)
 {
         unsigned long flags, pfn, pfninc = 1;
         unsigned int i, level;
         pte_t *pbase, *tmp;
         pgprot_t ref_prot;
-        struct page *base;
+        struct page *base = alloc_pages(GFP_KERNEL, 0);
+        if (!base)
+                return -ENOMEM;
 
-        /*
-         * Get a page from the pool. The pool list is protected by the
-         * pgd_lock, which we have to take anyway for the split
-         * operation:
-         */
         spin_lock_irqsave(&pgd_lock, flags);
-        if (list_empty(&page_pool)) {
-                spin_unlock_irqrestore(&pgd_lock, flags);
-                base = NULL;
-                cpa_fill_pool(&base);
-                if (!base)
-                        return -ENOMEM;
-                spin_lock_irqsave(&pgd_lock, flags);
-        } else {
-                base = list_first_entry(&page_pool, struct page, lru);
-                list_del(&base->lru);
-                pool_pages--;
-
-                if (pool_pages < pool_low)
-                        pool_low = pool_pages;
-        }
-
         /*
          * Check for races, another CPU might have split this page
          * up for us already:
@@ -611,11 +514,8 @@ out_unlock:
          * If we dropped out via the lookup_address check under
          * pgd_lock then stick the page back into the pool:
          */
-        if (base) {
-                list_add(&base->lru, &page_pool);
-                pool_pages++;
-        } else
-                pool_used++;
+        if (base)
+                __free_page(base);
         spin_unlock_irqrestore(&pgd_lock, flags);
 
         return 0;
@@ -899,8 +799,6 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
                 cpa_flush_all(cache);
 
 out:
-        cpa_fill_pool(NULL);
-
         return ret;
 }
 
@@ -1178,53 +1076,8 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
          * but that can deadlock->flush only current cpu:
          */
         __flush_tlb_all();
-
-        /*
-         * Try to refill the page pool here. We can do this only after
-         * the tlb flush.
-         */
-        cpa_fill_pool(NULL);
-}
-
-#ifdef CONFIG_DEBUG_FS
-static int dpa_show(struct seq_file *m, void *v)
-{
-        seq_puts(m, "DEBUG_PAGEALLOC\n");
-        seq_printf(m, "pool_size     : %lu\n", pool_size);
-        seq_printf(m, "pool_pages    : %lu\n", pool_pages);
-        seq_printf(m, "pool_low      : %lu\n", pool_low);
-        seq_printf(m, "pool_used     : %lu\n", pool_used);
-        seq_printf(m, "pool_failed   : %lu\n", pool_failed);
-
-        return 0;
-}
-
-static int dpa_open(struct inode *inode, struct file *filp)
-{
-        return single_open(filp, dpa_show, NULL);
 }
 
-static const struct file_operations dpa_fops = {
-        .open           = dpa_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = single_release,
-};
-
-static int __init debug_pagealloc_proc_init(void)
-{
-        struct dentry *de;
-
-        de = debugfs_create_file("debug_pagealloc", 0600, NULL, NULL,
-                                 &dpa_fops);
-        if (!de)
-                return -ENOMEM;
-
-        return 0;
-}
-__initcall(debug_pagealloc_proc_init);
-#endif
-
 #ifdef CONFIG_HIBERNATION
 
 bool kernel_page_present(struct page *page)