From 0313e6ddde2b423cba94169f81d4243b7f54390e Mon Sep 17 00:00:00 2001
From: Tao Zeng <tao.zeng@amlogic.com>
Date: Thu, 6 Dec 2018 15:24:44 +0800
Subject: [PATCH] mm: subtract CMA isolated pages when allocate TVP [1/1]

PD#SWPL-2933

Problem:
When allocate CMA pages in buildroot enverioment, system will
hung in congestion_wait:
Call trace:
[<ffffff8009086a78>] __switch_to+0xa0/0xc8
[<ffffff8009de3eb8>] __schedule+0x268/0x7d8
[<ffffff8009de4464>] schedule+0x3c/0xa0
[<ffffff8009de7c9c>] schedule_timeout+0x1b4/0x448
[<ffffff8009de3be8>] io_schedule_timeout+0x98/0x100
[<ffffff80091e3fb8>] congestion_wait+0x90/0x190
[<ffffff80091ebcf4>] isolate_migratepages_block+0x7ec/0x890
[<ffffff80091ec794>] isolate_migratepages_range+0x8c/0x100
[<ffffff8009a8f34c>] aml_alloc_contig_migrate_range+0x104/0x158
[<ffffff8009a8f518>] cma_boost_work_func+0x178/0x270
[<ffffff80090cc228>] kthread+0xf8/0x110
[<ffffff80090836c0>] ret_from_fork+0x10/0x50

Solution:
subtract isolated CMA pages when allocation large CMA for TVP.

Verify:
local

Change-Id: I96153cf104abb009a8965c2230a5242e495dd031
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>
---
 mm/compaction.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/mm/compaction.c b/mm/compaction.c
index 2d9ee59ff2b1..e35f49150e2b 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -637,7 +637,11 @@ isolate_freepages_range(struct compact_control *cc,
 /* Similar to reclaim, but different enough that they don't share logic */
 static bool too_many_isolated(struct zone *zone)
 {
+#ifdef CONFIG_AMLOGIC_CMA
+	signed long active, inactive, isolated;
+#else
 	unsigned long active, inactive, isolated;
+#endif
 
 	inactive = node_page_state(zone->zone_pgdat, NR_INACTIVE_FILE) +
 			node_page_state(zone->zone_pgdat, NR_INACTIVE_ANON);
@@ -646,6 +650,13 @@ static bool too_many_isolated(struct zone *zone)
 	isolated = node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE) +
 			node_page_state(zone->zone_pgdat, NR_ISOLATED_ANON);
 
+#ifdef CONFIG_AMLOGIC_CMA
+	isolated -= global_page_state(NR_CMA_ISOLATED);
+	WARN_ONCE(isolated > (inactive + active) / 2,
+		  "isolated:%ld, cma:%ld, inactive:%ld, active:%ld\n",
+		  isolated, global_page_state(NR_CMA_ISOLATED),
+		  inactive, active);
+#endif /* CONFIG_AMLOGIC_CMA */
 	return isolated > (inactive + active) / 2;
 }
 #ifdef CONFIG_AMLOGIC_CMA
-- 
2.20.1