From: NeilBrown <neilb@suse.com>
To: Thomas Graf <tgraf@suug.ch>, Herbert Xu <herbert@gondor.apana.org.au>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 00/18] Assorted rhashtable improvements
Date: Fri, 01 Jun 2018 14:44:09 +1000 [thread overview]
Message-ID: <152782754287.30340.4395718227884933670.stgit@noble> (raw)
Hi,
the following is my current set of rhashtable improvements.
Some have been seen before, some have been improved,
others are new.
They include:
working list-nulls support
stability improvements for rhashtable_walk
bit-spin-locks for simplicity and reduced cache footprint
during modification
optional per-cpu locks to improve scalability for modificiation
various cleanups
If I get suitable acks I will send more focused subsets to Davem for
inclusion.
I had said previously that I thought there was a way to provide
stable walking of an rhl table in the face of concurrent
insert/delete. Having tried, I no longer think this can be
done without substantial impact to lookups and/or other operations.
The idea of attaching a marker to the list is incompatible with
the normal rules for working with rcu-protected lists ("attaching"
might be manageable. "moving" or "removing" is the problematic part).
The last patch is the one I'm least certain of. It seems like a good
idea to improve the chance of a walk avoiding any rehash, but it
cannot provide a solid guarantee without risking a denial-of-service.
My compromise is to guarantee no rehashes caused by shrinkage, and
discourage rehashes caused by growth. I'm not yet sure if that is
sufficiently valuable, but I thought I would include the patch in the
RFC anyway.
Thanks,
NeilBrown
---
NeilBrown (18):
rhashtable: silence RCU warning in rhashtable_test.
rhashtable: split rhashtable.h
rhashtable: remove nulls_base and related code.
rhashtable: detect when object movement might have invalidated a lookup
rhashtable: simplify INIT_RHT_NULLS_HEAD()
rhashtable: simplify nested_table_alloc() and rht_bucket_nested_insert()
rhashtable: use cmpxchg() to protect ->future_tbl.
rhashtable: clean up dereference of ->future_tbl.
rhashtable: use cmpxchg() in nested_table_alloc()
rhashtable: remove rhashtable_walk_peek()
rhashtable: further improve stability of rhashtable_walk
rhashtable: add rhashtable_walk_prev()
rhashtable: don't hold lock on first table throughout insertion.
rhashtable: allow rht_bucket_var to return NULL.
rhashtable: use bit_spin_locks to protect hash bucket.
rhashtable: allow percpu element counter
rhashtable: rename rht_for_each*continue as *from.
rhashtable: add rhashtable_walk_delay_rehash()
.clang-format | 8
MAINTAINERS | 2
drivers/net/ethernet/chelsio/cxgb4/cxgb4.h | 1
drivers/staging/lustre/lustre/fid/fid_request.c | 2
drivers/staging/lustre/lustre/fld/fld_request.c | 1
drivers/staging/lustre/lustre/include/lu_object.h | 1
include/linux/ipc.h | 2
include/linux/ipc_namespace.h | 2
include/linux/mroute_base.h | 2
include/linux/percpu_counter.h | 4
include/linux/rhashtable-types.h | 147 ++++++
include/linux/rhashtable.h | 537 +++++++++++----------
include/net/inet_frag.h | 2
include/net/netfilter/nf_flow_table.h | 2
include/net/sctp/structs.h | 2
include/net/seg6.h | 2
include/net/seg6_hmac.h | 2
ipc/msg.c | 1
ipc/sem.c | 1
ipc/shm.c | 1
ipc/util.c | 2
lib/rhashtable.c | 481 +++++++++++--------
lib/test_rhashtable.c | 22 +
net/bridge/br_fdb.c | 1
net/bridge/br_vlan.c | 1
net/bridge/br_vlan_tunnel.c | 1
net/ipv4/inet_fragment.c | 1
net/ipv4/ipmr.c | 2
net/ipv4/ipmr_base.c | 1
net/ipv6/ip6mr.c | 2
net/ipv6/seg6.c | 1
net/ipv6/seg6_hmac.c | 1
net/netfilter/nf_tables_api.c | 1
net/sctp/input.c | 1
net/sctp/socket.c | 1
35 files changed, 760 insertions(+), 481 deletions(-)
create mode 100644 include/linux/rhashtable-types.h
--
Signature
next reply other threads:[~2018-06-01 4:45 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-01 4:44 NeilBrown [this message]
2018-06-01 4:44 ` [PATCH 11/18] rhashtable: further improve stability of rhashtable_walk NeilBrown
2018-06-01 4:44 ` [PATCH 17/18] rhashtable: rename rht_for_each*continue as *from NeilBrown
2018-06-01 4:44 ` [PATCH 10/18] rhashtable: remove rhashtable_walk_peek() NeilBrown
2018-06-02 15:48 ` Herbert Xu
2018-06-04 0:30 ` NeilBrown
2018-06-04 1:18 ` Tom Herbert
2018-06-04 2:09 ` NeilBrown
2018-06-04 21:31 ` Tom Herbert
2018-06-04 22:13 ` Tom Herbert
2018-06-05 1:24 ` NeilBrown
2018-06-05 1:00 ` NeilBrown
[not found] ` <CALx6S36Ce-rXQMzmFYZVPGD10Bo6udvRAHiZ5gWwnzVwoTVv0w@mail.gmail.com>
2018-06-06 5:07 ` NeilBrown
2018-06-07 2:45 ` [PATCH - RFC] rhashtable: add rhashtable_walk_last_seen() NeilBrown
2018-06-07 2:46 ` [PATCH - RFC] rhashtable: implement rhashtable_walk_peek() using rhashtable_walk_last_seen() NeilBrown
[not found] ` <CALx6S35GgUOd0dPgv7P96wNNTv5pN7fij0pcAoccqcSWZhvY7Q@mail.gmail.com>
2018-06-12 2:48 ` [PATCH RFC v2] " NeilBrown
2018-06-14 17:41 ` Tom Herbert
2018-06-15 4:23 ` Herbert Xu
2018-06-15 5:31 ` NeilBrown
2018-06-01 4:44 ` [PATCH 18/18] rhashtable: add rhashtable_walk_delay_rehash() NeilBrown
2018-06-01 4:44 ` [PATCH 14/18] rhashtable: allow rht_bucket_var to return NULL NeilBrown
2018-06-01 4:44 ` [PATCH 15/18] rhashtable: use bit_spin_locks to protect hash bucket NeilBrown
2018-06-02 5:03 ` Herbert Xu
2018-06-02 9:53 ` Eric Dumazet
2018-06-04 0:25 ` NeilBrown
2018-06-04 2:52 ` [PATCH 15a/18] rhashtables: add lockdep tracking to bucket bit-spin-locks NeilBrown
2018-06-04 18:16 ` Simon Horman
2018-06-04 21:37 ` NeilBrown
2018-06-01 4:44 ` [PATCH 01/18] rhashtable: silence RCU warning in rhashtable_test NeilBrown
2018-06-01 4:44 ` [PATCH 07/18] rhashtable: use cmpxchg() to protect ->future_tbl NeilBrown
2018-06-01 16:44 ` Herbert Xu
2018-06-01 4:44 ` [PATCH 13/18] rhashtable: don't hold lock on first table throughout insertion NeilBrown
2018-06-01 4:44 ` [PATCH 16/18] rhashtable: allow percpu element counter NeilBrown
2018-06-01 4:44 ` [PATCH 03/18] rhashtable: remove nulls_base and related code NeilBrown
2018-06-07 2:49 ` NeilBrown
2018-06-13 6:25 ` Herbert Xu
2018-06-01 4:44 ` [PATCH 08/18] rhashtable: clean up dereference of ->future_tbl NeilBrown
2018-06-01 16:54 ` Herbert Xu
2018-06-01 4:44 ` [PATCH 06/18] rhashtable: simplify nested_table_alloc() and rht_bucket_nested_insert() NeilBrown
2018-06-01 16:28 ` Herbert Xu
2018-06-01 4:44 ` [PATCH 09/18] rhashtable: use cmpxchg() in nested_table_alloc() NeilBrown
2018-06-01 4:44 ` [PATCH 05/18] rhashtable: simplify INIT_RHT_NULLS_HEAD() NeilBrown
2018-06-01 16:24 ` Herbert Xu
2018-06-01 4:44 ` [PATCH 12/18] rhashtable: add rhashtable_walk_prev() NeilBrown
2018-06-01 4:44 ` [PATCH 02/18] rhashtable: split rhashtable.h NeilBrown
2018-06-01 10:48 ` Herbert Xu
2018-06-01 4:44 ` [PATCH 04/18] rhashtable: detect when object movement might have invalidated a lookup NeilBrown
2018-06-01 16:06 ` Herbert Xu
2018-06-04 3:38 ` NeilBrown
2018-07-06 7:08 ` [PATCH resend] " NeilBrown
2018-07-12 5:46 ` David Miller
2018-07-12 5:48 ` David Miller
2018-07-15 23:55 ` NeilBrown
2018-07-15 23:57 ` [PATCH - revised] " NeilBrown
2018-07-16 0:51 ` Herbert Xu
2018-07-16 1:23 ` NeilBrown
2018-07-16 2:16 ` Herbert Xu
2018-07-16 3:26 ` NeilBrown
2018-07-17 6:30 ` Herbert Xu
2018-07-20 6:24 ` NeilBrown
2018-07-18 20:14 ` David Miller
2018-07-20 6:30 ` NeilBrown
2018-07-20 6:43 ` David Miller
2018-07-20 7:09 ` NeilBrown
2018-07-23 1:56 ` [PATCH net-next] rhashtable: detect when object movement between tables " NeilBrown
2018-07-26 20:55 ` David Miller
2018-07-26 22:04 ` NeilBrown
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