[LU-8130] Migrate from libcfs hash to rhashtable

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Fix Version/s: Upstream
• Affects Version/s: Lustre 2.9.0
• Assignee: James A Simmons
• Reporter: James A Simmons

Description

The linux kernel has its own resizable hashtable which can be used in place of libcfs hash code. The linux rhashtable was developed for the networking layer and that layer has very high requirements for performance. Some of the benefits are low latency as well as lockless lookups. Migrating Lustre to rhashtable should mean HUGE PERFORMANCE gains!!!!!

Issue Links

• is blocking: LU-14535 add option for LFS to get all quota information
• is related to: LU-14698 sanityn test_77b scheduling in_atomic()
• is related to: LU-16365 cached 'ls -l' is slow
• is related to: LU-18031 soft lockup in cfs_hash_for_each_relax
• is related to: LU-18187 BUG: KASAN: vmalloc-out-of-bounds in ldlm_reclaim_lock_cb+0xa46/0xa50 [ptlrpc]
• is related to: LU-6800 Significant performance regression with patch LU-5264
• is related to: LU-11624 BUG: unable to handle kernel NULL pointer at nid_hash()
• is related to: LU-14752 LustreError: 3594004:0:(lu_object.c:2472:lu_object_assign_fid()) ASSERTION( rc == 0 ) failed: failed hashtable insertion: rc = -16
• is related to: LU-10401 sanity test_133g: timeout during MDT mount
• is related to: LU-16253 sanityn: ASSERTION( orro->oo_ref == 0 ) in 77d
• is related to: LU-17191 sanity-quota test_1b, 1d, 1f, 1i: FAIL: user write success, but expect EDQUOT
• is related to: LU-17793 warning: objtool: __cfs_fail_check_set() falls through to next function __cfs_fail_timeout_set()
• is related to: LU-17329 Relaxed POSIX Consistency for Lustre
• is related to: LU-12511 Prepare lustre for adoption into the linux kernel
• is related to: LU-18351 Job stats scaling
• is related to: LU-9859 libcfs simplification