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 dd20b01771c4bd2..2433d3c29b49ff2 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1746,15 +1746,16 @@ 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 = {}; 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, -- 2.26.0.106.g9fadedd _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu