On 2021-08-11 12:48, Zhen Lei wrote:
The obvious key to the performance optimization of commit 587e6c10a7ce
("iommu/arm-smmu-v3: Reduce contention during command-queue insertion") is
to allow multiple cores to insert commands in parallel after a brief mutex
contention.
Obviously, inserting as many commands at a time as possible can reduce the
number of times the mutex contention participates, thereby improving the
overall performance. At least it reduces the number of calls to function
arm_smmu_cmdq_issue_cmdlist().
Therefore, use command queue batching helpers to insert multiple commands
at a time.
Signed-off-by: Zhen Lei <thunder.leiz...@huawei.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 235f9bdaeaf223b..c81cd929047f573 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1747,15 +1747,16 @@ static int arm_smmu_atc_inv_master(struct
arm_smmu_master *master)
{
int i;
struct arm_smmu_cmdq_ent cmd;
+ struct arm_smmu_cmdq_batch cmds = {};
BTW, it looks like this has crossed over with John's patch removing these.
Robin.
arm_smmu_atc_inv_to_cmd(0, 0, 0, &cmd);
for (i = 0; i < master->num_streams; i++) {
cmd.atc.sid = master->streams[i].id;
- arm_smmu_cmdq_issue_cmd(master->smmu, &cmd);
+ arm_smmu_cmdq_batch_add(master->smmu, &cmds, &cmd);
}
- return arm_smmu_cmdq_issue_sync(master->smmu);
+ return arm_smmu_cmdq_batch_submit(master->smmu, &cmds);
}
int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
