mm: fix dead loop if signal pending for cma alloc task [1/1]

PD#GH-17

Problem:
If a task be killed during CMA allocation, then it will abort
cma allocation in function compact_unlock_should_abort. But in
function aml_cma_alloc_range, it will return -EBUSY. Which cause
cma allocation loop won't exit and run again and again.

Solution:
return -EINT for this case to exit cma allocaion loop.

Verify:
newman platform

Change-Id: I6559bb184fc035ae68c8ccd001407767e1e22f0c
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>

drivers/amlogic/memory_ext/aml_cma.c

@@ -577,6 +577,7 @@ int aml_cma_alloc_range(unsigned long start, unsigned long end)
 		.mode = MIGRATE_SYNC,
 		.page_type = COMPACT_CMA,
 		.ignore_skip_hint = true,
+		.contended = false,
 	};
 	INIT_LIST_HEAD(&cc.migratepages);
 
@@ -611,11 +612,8 @@ int aml_cma_alloc_range(unsigned long start, unsigned long end)
 	outer_start = start;
 	while (!PageBuddy(pfn_to_page(outer_start))) {
 		if (++order >= MAX_ORDER) {
-			ret = -EBUSY;
-			try_times++;
-			if (try_times < 10)
-				goto try_again;
-			goto done;
+			outer_start = start;
+			break;
 		}
 		outer_start &= ~0UL << order;
 	}
@@ -647,7 +645,11 @@ int aml_cma_alloc_range(unsigned long start, unsigned long end)
 	/* Grab isolated pages from freelists. */
 	outer_end = isolate_freepages_range(&cc, outer_start, end);
 	if (!outer_end) {
-		ret = -EBUSY;
+		if (cc.contended) {
+			ret = -EINTR;
+			pr_info("cma_alloc [%lx-%lx] aborted\n", start, end);
+		} else
+			ret = -EBUSY;
 		goto done;
 	}