mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2025-01-19 17:56:10 +07:00
3994586f4d
Currently mmap_sem is read locked while pinning the memory. In a multi-threaded application of a process, holding mmap_sem lock creates contention with other threads who might be either registering memory, creating QPs or simply doing mmap() as such operations also require to hold the mmap_sem write lock. All such operation cannot make forward progress until one memory pin operation is completed. It becomes more worse if the memory is unpinned and/or memory registration is large (in GB range). Therefore, instead of holding mmap_sem for too long (for whole region pinning), acquire and release the lock for every few pages. For example on x86 with 4K page size, acquire and release mmap_sem for every 2Mbytes memory chunk. This allows other competing threads to make progress who might wish to hold mmap_sem for shorter duration. When memory registration latency is measured using [1] for memory sizes ranging from 4K to 48GB, <= 1% or 0.5% degradation is noticed. In many runs no difference is seen other than run-to-run variance. In other targeted tests of users with large memory, desired improvements are seen due to reduced contention of mmap_sem. [1] https://github.com/paravmellanox/rtool $ rdma_resource_lat -c 1 -s 48G -a -u L -i 500 -A It registers pinned memory from 4K to 48GB size with 500 iterations for each memory size. $ rdma_resource_lat -c 1 -s 12G -a -u L -i 500 -t 4 4 competing threads pin memory, each of 12GB size with 500 iterations. Signed-off-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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| .. | ||
| addr.c | ||
| agent.c | ||
| agent.h | ||
| cache.c | ||
| cgroup.c | ||
| cm_msgs.h | ||
| cm.c | ||
| cma_configfs.c | ||
| cma_priv.h | ||
| cma.c | ||
| core_priv.h | ||
| cq.c | ||
| device.c | ||
| fmr_pool.c | ||
| iwcm.c | ||
| iwcm.h | ||
| iwpm_msg.c | ||
| iwpm_util.c | ||
| iwpm_util.h | ||
| mad_priv.h | ||
| mad_rmpp.c | ||
| mad_rmpp.h | ||
| mad.c | ||
| Makefile | ||
| mr_pool.c | ||
| multicast.c | ||
| netlink.c | ||
| nldev.c | ||
| opa_smi.h | ||
| packer.c | ||
| rdma_core.c | ||
| rdma_core.h | ||
| restrack.c | ||
| roce_gid_mgmt.c | ||
| rw.c | ||
| sa_query.c | ||
| sa.h | ||
| security.c | ||
| smi.c | ||
| smi.h | ||
| sysfs.c | ||
| ucm.c | ||
| ucma.c | ||
| ud_header.c | ||
| umem_odp.c | ||
| umem.c | ||
| user_mad.c | ||
| uverbs_cmd.c | ||
| uverbs_ioctl.c | ||
| uverbs_main.c | ||
| uverbs_marshall.c | ||
| uverbs_std_types_counters.c | ||
| uverbs_std_types_cq.c | ||
| uverbs_std_types_dm.c | ||
| uverbs_std_types_flow_action.c | ||
| uverbs_std_types_mr.c | ||
| uverbs_std_types.c | ||
| uverbs_uapi.c | ||
| uverbs.h | ||
| verbs.c | ||