blk-mq: limit memory consumption if a crash dump is active

[linux-drm-fsl-dcu.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3b277b4eaa95ac8d08d185bc1ab5a9cc99c684c9..c5345a95182035901820553d6606c49dc3a388f1 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -20,6 +20,7 @@
 #include <linux/cache.h>
 #include <linux/sched/sysctl.h>
 #include <linux/delay.h>
+#include <linux/crash_dump.h>
 
 #include <trace/events/block.h>
 
@@ -1742,6 +1743,16 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
        if (!ctx)
                return ERR_PTR(-ENOMEM);
 
+       /*
+        * If a crashdump is active, then we are potentially in a very
+        * memory constrained environment. Limit us to 1 queue and
+        * 64 tags to prevent using too much memory.
+        */
+       if (is_kdump_kernel()) {
+               set->nr_hw_queues = 1;
+               set->queue_depth = min(64U, set->queue_depth);
+       }
+
        hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
                        set->numa_node);