[patch 6/7] x86, cpa: remove cpa pool code
From: Suresh Siddha
Date: Tue Sep 23 2008 - 17:22:39 EST
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@xxxxxxxxx>
---
Index: tip/arch/x86/mm/pageattr.c
===================================================================
--- tip.orig/arch/x86/mm/pageattr.c 2008-09-23 13:47:45.000000000 -0700
+++ tip/arch/x86/mm/pageattr.c 2008-09-23 13:47:51.000000000 -0700
@@ -447,114 +447,17 @@
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 @@
* 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 @@
cpa_flush_all(cache);
out:
- cpa_fill_pool(NULL);
-
return ret;
}
@@ -1178,53 +1076,8 @@
* 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)
Index: tip/arch/x86/mm/init_64.c
===================================================================
--- tip.orig/arch/x86/mm/init_64.c 2008-09-23 13:46:14.000000000 -0700
+++ tip/arch/x86/mm/init_64.c 2008-09-23 13:47:51.000000000 -0700
@@ -944,8 +944,6 @@
reservedpages << (PAGE_SHIFT-10),
datasize >> 10,
initsize >> 10);
-
- cpa_init();
}
void free_init_pages(char *what, unsigned long begin, unsigned long end)
Index: tip/arch/x86/mm/init_32.c
===================================================================
--- tip.orig/arch/x86/mm/init_32.c 2008-09-23 13:46:14.000000000 -0700
+++ tip/arch/x86/mm/init_32.c 2008-09-23 13:47:51.000000000 -0700
@@ -1053,7 +1053,6 @@
if (boot_cpu_data.wp_works_ok < 0)
test_wp_bit();
- cpa_init();
save_pg_dir();
zap_low_mappings();
}
Index: tip/include/asm-x86/cacheflush.h
===================================================================
--- tip.orig/include/asm-x86/cacheflush.h 2008-09-23 13:45:48.000000000 -0700
+++ tip/include/asm-x86/cacheflush.h 2008-09-23 13:47:51.000000000 -0700
@@ -99,8 +99,6 @@
void clflush_cache_range(void *addr, unsigned int size);
-void cpa_init(void);
-
#ifdef CONFIG_DEBUG_RODATA
void mark_rodata_ro(void);
extern const int rodata_test_data;
--
--
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