linux-kernel - [PATCH tip/core/rcu 0/10] No-CBs contention-reduction updates for v5.3-rc2

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 1 Aug 2019 16:16:19 -0700
From:   "Paul E. McKenney" <paulmck@...ux.ibm.com>
To:     rcu@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, mingo@...nel.org,
        jiangshanlai@...il.com, dipankar@...ibm.com,
        akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
        josh@...htriplett.org, tglx@...utronix.de, peterz@...radead.org,
        rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
        fweisbec@...il.com, oleg@...hat.com, joel@...lfernandes.org
Subject: [PATCH tip/core/rcu 0/10] No-CBs contention-reduction updates for
 v5.3-rc2

Hello!

This series partially addresses lock-contention increases caused by the
move to the ->cblist segmented callback list.

1.	Enable re-awakening under high callback load.

2.	Never downgrade ->nocb_defer_wakeup in wake_nocb_gp_defer().

3.	Make __call_rcu_nocb_wake() safe for many callbacks.

4.	Avoid needless wakeups of no-CBs grace-period kthread.

5.	Avoid ->nocb_lock capture by corresponding CPU.

6.	Round down for number of no-CBs grace-period kthreads.

7.	Reduce contention at no-CBs registry-time CB advancement.

8.	Reduce contention at no-CBs invocation-done time.

9.	Reduce ->nocb_lock contention with separate ->nocb_gp_lock.

10.	Unconditionally advance and wake for excessive CBs.

							Thanx, Paul

------------------------------------------------------------------------

 tree.c        |   20 ++++++++-
 tree.h        |   21 ++++++++-
 tree_plugin.h |  128 ++++++++++++++++++++++++++++++++++++----------------------
 3 files changed, 118 insertions(+), 51 deletions(-)