!1244 set the iova rcache global

Merge Pull Request from: @ci-robot 
 
PR sync from: Zhang Zekun <zhangzekun11@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/QTEAS342W3GWUZ4HON7LSTQKXGLF5G3K/ 
The iova rcache will have performance problem, set the iova rcache
global mag max size to 128 to fix it.

Zhang Zekun (2):
  iommu/iova: increase the iova_rcache depot max size
  config: enable set the max iova mag size to 128


-- 
2.17.1
 
 
Link:https://gitee.com/openeuler/kernel/pulls/1244 

Reviewed-by: Zheng Zengkai <zhengzengkai@huawei.com> 
Reviewed-by: Liu Chao <liuchao173@huawei.com> 
Reviewed-by: Weilong Chen <chenweilong@huawei.com> 
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> 

arch/arm64/configs/openeuler_defconfig

@@ -5950,6 +5950,7 @@ CONFIG_ARM_SMMU_V3_PM=y
 # CONFIG_QCOM_IOMMU is not set
 # CONFIG_VIRTIO_IOMMU is not set
 CONFIG_SMMU_BYPASS_DEV=y
+CONFIG_IOVA_MAX_GLOBAL_MAGS=128
 
 #
 # Remoteproc drivers

drivers/iommu/Kconfig

@@ -437,5 +437,15 @@ config SMMU_BYPASS_DEV
 
 	  This feature will be replaced by ACPI IORT RMR node, which will be
 	  upstreamed in mainline.
+config IOVA_MAX_GLOBAL_MAGS
+	int "Set the max iova global magzines in iova rcache"
+	range 16 2048
+	default "32"
+	help
+	  Iova rcache global magizine is shared among every cpu. The size of
+	  it can be a bottle neck when lots of cpus are contending to use it.
+	  If you are suffering from the speed of allocing iova with more than
+	  128 cpus, try to tune this config larger.
+
 
 endif # IOMMU_SUPPORT

include/linux/iova.h

@@ -26,7 +26,7 @@ struct iova_magazine;
 struct iova_cpu_rcache;
 
 #define IOVA_RANGE_CACHE_MAX_SIZE 6	/* log of max cached IOVA range size (in pages) */
-#define MAX_GLOBAL_MAGS 32	/* magazines per bin */
+#define MAX_GLOBAL_MAGS CONFIG_IOVA_MAX_GLOBAL_MAGS	/* magazines per bin */
 
 struct iova_rcache {
 	spinlock_t lock;