mm: add cma debug interafce [1/1]

PD#GH-17

Problem:
sometimes cma allocation failed but it's hard to get
failed log and need recompile code.

Solution:
Add /proc/cma_debug to open cma debug message dynamic.
By default, no debug message is printed. If you write a
value large than 0 to this node, debug message will be
printed.

Verify:
p212

Change-Id: Ibcfd1d48be5f33f674f09df713dc2e493748c405
Signed-off-by: tao zeng <tao.zeng@amlogic.com>

drivers/amlogic/memory_ext/aml_cma.c

@@ -30,11 +30,14 @@
 #include <linux/spinlock_types.h>
 #include <linux/amlogic/aml_cma.h>
 #include <linux/hugetlb.h>
+#include <linux/proc_fs.h>
 #include <trace/events/page_isolation.h>
 #ifdef CONFIG_AMLOGIC_PAGE_TRACE
 #include <linux/amlogic/page_trace.h>
 #endif /* CONFIG_AMLOGIC_PAGE_TRACE */
 
+#define MAX_DEBUG_LEVEL		5
+
 struct work_cma {
 	struct list_head list;
 	unsigned long pfn;
@@ -52,6 +55,8 @@ struct cma_pcp {
 
 static bool can_boost;
 static DEFINE_PER_CPU(struct cma_pcp, cma_pcp_thread);
+static struct proc_dir_entry *dentry;
+int cma_debug_level;
 
 DEFINE_SPINLOCK(cma_iso_lock);
 static atomic_t cma_allocate;
@@ -261,6 +266,7 @@ static int aml_alloc_contig_migrate_range(struct compact_control *cc,
 			pfn = isolate_migratepages_range(cc, pfn, end);
 			if (!pfn) {
 				ret = -EINTR;
+				cma_debug(1, NULL, " iso migrate page fail\n");
 				break;
 			}
 			tries = 0;
@@ -336,7 +342,7 @@ static int cma_boost_work_func(void *cma_data)
 			drain_local_pages(NULL);
 		}
 		if (ret)
-			pr_debug("%s, failed, ret:%d\n", __func__, ret);
+			cma_debug(1, NULL, "failed, ret:%d\n", ret);
 next:
 		complete(&c_work->end);
 		if (kthread_should_stop()) {
@@ -441,34 +447,6 @@ int cma_alloc_contig_boost(unsigned long start_pfn, unsigned long count)
 	return ret;
 }
 
-/*
- * Some of these functions are implemented from page_isolate.c
- */
-static bool can_free_list_page(struct page *page, struct list_head *list)
-{
-#if 0
-	unsigned long flags;
-	bool ret = false;
-
-	if (!spin_trylock_irqsave(&cma_iso_lock, flags))
-		return ret;
-
-	if (!(page->flags & PAGE_FLAGS_CHECK_AT_FREE) &&
-	    !PageSwapBacked(page) &&
-	    (page->lru.next != LIST_POISON1)) {
-		if (list_empty(&page->lru))
-			list_add(&page->lru, list);
-		else
-			list_move(&page->lru, list);
-		ret = true;
-	}
-	spin_unlock_irqrestore(&cma_iso_lock, flags);
-	return ret;
-#else
-	return false;
-#endif
-}
-
 static int __aml_check_pageblock_isolate(unsigned long pfn,
 					 unsigned long end_pfn,
 					 bool skip_hwpoisoned_pages,
@@ -496,13 +474,7 @@ static int __aml_check_pageblock_isolate(unsigned long pfn,
 			 */
 			pfn++;
 		} else {
-			/* This page can be freed ? */
-			if (!page_count(page)) {
-				if (can_free_list_page(page, list)) {
-					pfn++;
-					continue;
-				}
-			}
+			cma_debug(1, page, " isolate failed\n");
 			break;
 		}
 	}
@@ -581,11 +553,14 @@ int aml_cma_alloc_range(unsigned long start, unsigned long end)
 	};
 	INIT_LIST_HEAD(&cc.migratepages);
 
+	cma_debug(0, NULL, " range [%lx-%lx]\n", start, end);
 	ret = start_isolate_page_range(get_align_pfn_low(start),
 				       get_align_pfn_high(end), MIGRATE_CMA,
 				       false);
-	if (ret)
+	if (ret) {
+		cma_debug(1, NULL, "ret:%d\n", ret);
 		return ret;
+	}
 
 try_again:
 	/*
@@ -600,8 +575,10 @@ try_again:
 	} else
 		ret = aml_alloc_contig_migrate_range(&cc, start, end, 0);
 
-	if (ret && ret != -EBUSY)
+	if (ret && ret != -EBUSY) {
+		cma_debug(1, NULL, "ret:%d\n", ret);
 		goto done;
+	}
 
 	ret = 0;
 	if (!boost_ok) {
@@ -633,8 +610,8 @@ try_again:
 
 	/* Make sure the range is really isolated. */
 	if (aml_check_pages_isolated(outer_start, end, false)) {
-		pr_debug("%s check_pages_isolated(%lx, %lx) failed\n",
-			 __func__, outer_start, end);
+		cma_debug(1, NULL, "check page isolate(%lx, %lx) failed\n",
+			  outer_start, end);
 		try_times++;
 		if (try_times < 10)
 			goto try_again;
@@ -650,6 +627,8 @@ try_again:
 			pr_info("cma_alloc [%lx-%lx] aborted\n", start, end);
 		} else
 			ret = -EBUSY;
+		cma_debug(1, NULL, "iso free range(%lx, %lx) failed\n",
+			  outer_start, end);
 		goto done;
 	}
 
@@ -733,11 +712,67 @@ void aml_cma_free(unsigned long pfn, unsigned int nr_pages)
 }
 EXPORT_SYMBOL(aml_cma_free);
 
+void show_page(struct page *page)
+{
+	unsigned long trace = 0;
+
+	if (!page)
+		return;
+#ifdef CONFIG_AMLOGIC_PAGE_TRACE
+	trace = get_page_trace(page);
+#endif
+	pr_info("page:%lx, map:%p, f:%lx, m:%d, c:%d, f:%pf\n",
+		page_to_pfn(page), page->mapping,
+		page->flags & 0xffffffff,
+		page_mapcount(page), page_count(page),
+		(void *)trace);
+}
+
+static int cma_debug_show(struct seq_file *m, void *arg)
+{
+	seq_printf(m, "level=%d\n", cma_debug_level);
+	return 0;
+}
+
+static ssize_t cma_debug_write(struct file *file, const char __user *buffer,
+			      size_t count, loff_t *ppos)
+{
+	int arg = 0;
+
+	if (kstrtoint_from_user(buffer, count, 10, &arg))
+		return -EINVAL;
+
+	if (arg > MAX_DEBUG_LEVEL)
+		return -EINVAL;
+
+	cma_debug_level = arg;
+	return count;
+}
+
+static int cma_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, cma_debug_show, NULL);
+}
+
+static const struct file_operations cma_dbg_file_ops = {
+	.open		= cma_debug_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.write		= cma_debug_write,
+	.release	= single_release,
+};
+
 static int __init aml_cma_init(void)
 {
 	atomic_set(&cma_allocate, 0);
 	atomic_long_set(&nr_cma_allocated, 0);
 
+	dentry = proc_create("cma_debug", 0644, NULL, &cma_dbg_file_ops);
+	if (IS_ERR_OR_NULL(dentry)) {
+		pr_err("%s, create sysfs failed\n", __func__);
+		return -1;
+	}
+
 	return 0;
 }
 arch_initcall(aml_cma_init);

include/linux/amlogic/aml_cma.h

@@ -74,6 +74,7 @@ extern bool cma_page(struct page *page);
 extern unsigned long get_cma_allocated(void);
 extern unsigned long get_total_cmapages(void);
 extern spinlock_t cma_iso_lock;
+extern int cma_debug_level;
 extern int aml_cma_alloc_range(unsigned long start, unsigned long end);
 
 extern void aml_cma_free(unsigned long pfn, unsigned int nr_pages);
@@ -81,6 +82,7 @@ extern void aml_cma_free(unsigned long pfn, unsigned int nr_pages);
 extern unsigned long reclaim_clean_pages_from_list(struct zone *zone,
 		struct list_head *page_list);
 
+extern void show_page(struct page *page);
 unsigned long
 isolate_freepages_range(struct compact_control *cc,
 			unsigned long start_pfn, unsigned long end_pfn);
@@ -91,4 +93,14 @@ isolate_migratepages_range(struct compact_control *cc,
 struct page *compaction_cma_alloc(struct page *migratepage,
 				  unsigned long data,
 				  int **result);
+
+#define cma_debug(l, p, format, args...)	\
+	{								\
+		if (l < cma_debug_level) {				\
+			show_page(p);					\
+			pr_info("%s, %d "format, __func__, __LINE__, ##args); \
+		}							\
+	}
+
+
 #endif /* __AMLOGIC_CMA_H__ */

mm/cma.c

@@ -520,6 +520,10 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 	pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
 		 count, align);
 
+#ifdef CONFIG_AMLOGIC_CMA
+	cma_debug(0, NULL, "(cma %p, count %zu, align %d)\n",
+		  (void *)cma, count, align);
+#endif
 	if (!count)
 		return NULL;
 
@@ -581,6 +585,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 
 #ifdef CONFIG_AMLOGIC_CMA
 	aml_cma_alloc_post_hook(&dummy, count, page);
+	cma_debug(0, NULL, "return %p\n", page);
 #endif /* CONFIG_AMLOGIC_CMA */
 	pr_debug("%s(): returned %p\n", __func__, page);
 	return page;

mm/compaction.c

@@ -434,14 +434,34 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
 		 * contention, to give chance to IRQs. Abort if fatal signal
 		 * pending or async compaction detects need_resched()
 		 */
+	#ifdef CONFIG_AMLOGIC_CMA
+		if (!(blockpfn % SWAP_CLUSTER_MAX)
+		    && compact_unlock_should_abort(&cc->zone->lock, flags,
+								&locked, cc)) {
+			if (strict)
+				cma_debug(1, page, "abort, blk:%lx, swap:%ld\n",
+					  blockpfn, SWAP_CLUSTER_MAX);
+			break;
+		}
+	#else
 		if (!(blockpfn % SWAP_CLUSTER_MAX)
 		    && compact_unlock_should_abort(&cc->zone->lock, flags,
 								&locked, cc))
 			break;
+	#endif
 
 		nr_scanned++;
+	#ifdef CONFIG_AMLOGIC_CMA
+		if (!pfn_valid_within(blockpfn)) {
+			if (strict)
+				cma_debug(1, page, "invalid pfn:%lx\n",
+					  blockpfn);
+			goto isolate_fail;
+		}
+	#else
 		if (!pfn_valid_within(blockpfn))
 			goto isolate_fail;
+	#endif
 
 		if (!valid_page)
 			valid_page = page;
@@ -459,12 +479,25 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
 				blockpfn += (1UL << comp_order) - 1;
 				cursor += (1UL << comp_order) - 1;
 			}
-
+		#ifdef CONFIG_AMLOGIC_CMA
+			if (strict)
+				cma_debug(1, page, "compound page:%lx\n",
+					  page_to_pfn(page));
+		#endif
 			goto isolate_fail;
 		}
 
+	#ifdef CONFIG_AMLOGIC_CMA
+		if (!PageBuddy(page)) {
+			if (strict)
+				cma_debug(1, page, " NO buddy page1:%lx\n",
+					  page_to_pfn(page));
+			goto isolate_fail;
+		}
+	#else
 		if (!PageBuddy(page))
 			goto isolate_fail;
+	#endif
 
 		/*
 		 * If we already hold the lock, we can skip some rechecking.
@@ -484,19 +517,44 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
 			 */
 			locked = compact_trylock_irqsave(&cc->zone->lock,
 								&flags, cc);
+		#ifdef CONFIG_AMLOGIC_CMA
+			if (!locked) {
+				if (strict)
+					cma_debug(1, page, " lock failed:%lx\n",
+						  page_to_pfn(page));
+				break;
+			}
+			/* Recheck this is a buddy page under lock */
+			if (!PageBuddy(page)) {
+				if (strict)
+					cma_debug(1, page, " No buddy2:%lx\n",
+						  page_to_pfn(page));
+				goto isolate_fail;
+			}
+		#else
 			if (!locked)
 				break;
 
 			/* Recheck this is a buddy page under lock */
 			if (!PageBuddy(page))
 				goto isolate_fail;
+		#endif
 		}
 
 		/* Found a free page, will break it into order-0 pages */
 		order = page_order(page);
 		isolated = __isolate_free_page(page, order);
+	#ifdef CONFIG_AMLOGIC_CMA
+		if (!isolated) {
+			if (strict)
+				cma_debug(1, page, "iso free fail:%lx, o:%d\n",
+					  page_to_pfn(page), order);
+			break;
+		}
+	#else
 		if (!isolated)
 			break;
+	#endif
 		set_page_private(page, order);
 
 		total_isolated += isolated;
@@ -599,9 +657,17 @@ isolate_freepages_range(struct compact_control *cc,
 			block_end_pfn = min(block_end_pfn, end_pfn);
 		}
 
+	#ifdef CONFIG_AMLOGIC_CMA
+		if (!pageblock_pfn_to_page(block_start_pfn,
+					block_end_pfn, cc->zone)) {
+			cma_debug(1, NULL, " no page block\n");
+			break;
+		}
+	#else
 		if (!pageblock_pfn_to_page(block_start_pfn,
 					block_end_pfn, cc->zone))
 			break;
+	#endif
 
 		isolated = isolate_freepages_block(cc, &isolate_start_pfn,
 						block_end_pfn, &freelist, true);
@@ -611,8 +677,15 @@ isolate_freepages_range(struct compact_control *cc,
 		 * there are any holes in the block (ie. invalid PFNs or
 		 * non-free pages).
 		 */
+	#ifdef CONFIG_AMLOGIC_CMA
+		if (!isolated) {
+			cma_debug(1, NULL, " isolate free page failed\n");
+			break;
+		}
+	#else
 		if (!isolated)
 			break;
+	#endif
 
 		/*
 		 * If we managed to isolate pages, it is always (1 << n) *
@@ -626,6 +699,10 @@ isolate_freepages_range(struct compact_control *cc,
 
 	if (pfn < end_pfn) {
 		/* Loop terminated early, cleanup. */
+	#ifdef CONFIG_AMLOGIC_CMA
+		cma_debug(1, NULL, "pfn:%lx, end:%lx, start:%lx\n",
+			  pfn, end_pfn, start_pfn);
+	#endif
 		release_freepages(&freelist);
 		return 0;
 	}

mm/migrate.c

@@ -415,6 +415,11 @@ int migrate_page_move_mapping(struct address_space *mapping,
 
 	if (!mapping) {
 		/* Anonymous page without mapping */
+	#ifdef CONFIG_AMLOGIC_CMA
+		if (page_count(page) != expected_count)
+			cma_debug(2, page, " anon page cnt miss match, e:%d\n",
+				  expected_count);
+	#endif
 		if (page_count(page) != expected_count)
 			return -EAGAIN;
 
@@ -439,6 +444,10 @@ int migrate_page_move_mapping(struct address_space *mapping,
 	if (page_count(page) != expected_count ||
 		radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) {
 		spin_unlock_irq(&mapping->tree_lock);
+	#ifdef CONFIG_AMLOGIC_CMA
+		cma_debug(2, page, " anon page cnt miss match, e:%d, p:%d\n",
+			  expected_count, page_has_private(page));
+	#endif
 		return -EAGAIN;
 	}
 
@@ -1017,11 +1026,21 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 			goto out_unlock_both;
 		}
 	} else if (page_mapped(page)) {
+	#ifdef CONFIG_AMLOGIC_CMA
+		int ret;
+
+		ret = try_to_unmap(page,
+				   TTU_MIGRATION | TTU_IGNORE_MLOCK |
+				   TTU_IGNORE_ACCESS);
+		if (ret != SWAP_SUCCESS)
+			cma_debug(2, page, " unmap failed:%d\n", ret);
+	#else
 		/* Establish migration ptes */
 		VM_BUG_ON_PAGE(PageAnon(page) && !PageKsm(page) && !anon_vma,
 				page);
 		try_to_unmap(page,
 			TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+	#endif
 		page_was_mapped = 1;
 	}
 
@@ -1341,6 +1360,9 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 			switch(rc) {
 			case -ENOMEM:
 				nr_failed++;
+			#ifdef CONFIG_AMLOGIC_CMA
+				cma_debug(2, page, " NO MEM\n");
+			#endif
 				goto out;
 			case -EAGAIN:
 				retry++;
@@ -1356,6 +1378,9 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 				 * retried in the next outer loop.
 				 */
 				nr_failed++;
+			#ifdef CONFIG_AMLOGIC_CMA
+				cma_debug(2, page, " failed:%d\n", rc);
+			#endif
 				break;
 			}
 		}