From: "Paul E. McKenney" <paulmck@kernel.org>
To: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
rushikesh.s.kadam@intel.com, urezki@gmail.com,
neeraj.iitr10@gmail.com, frederic@kernel.org,
rostedt@goodmis.org, vineeth@bitbyteword.org,
boqun.feng@gmail.com
Subject: Re: [PATCH v5 00/18] Implement call_rcu_lazy() and miscellaneous fixes
Date: Sat, 3 Sep 2022 08:22:42 -0700 [thread overview]
Message-ID: <20220903152242.GA870876@paulmck-ThinkPad-P17-Gen-1> (raw)
In-Reply-To: <20220901221720.1105021-1-joel@joelfernandes.org>
On Thu, Sep 01, 2022 at 10:17:02PM +0000, Joel Fernandes (Google) wrote:
> Here is v5 of call_rcu_lazy() based on the latest RCU -dev branch. Main changes are:
> - moved length field into rcu_data (Frederic suggestion)
> - added new traces to aid debugging and testing.
> - the new trace patch (along with the rcuscale and rcutorture tests)
> gives confidence that the patches work well. Also it is tested on
> real ChromeOS hardware and the boot time is looking good even though
> lazy callbacks are being queued (i.e. the lazy ones do not effect the
> synchronous non-lazy ones that effect boot time)
> - rewrote some parts of the core patch.
> - for rcutop, please apply the diff in the following link to the BCC repo:
> https://lore.kernel.org/r/Yn+79v4q+1c9lXdc@google.com
> Then, cd libbpf-tools/ and run make to build the rcutop static binary.
> (If you need an x86 binary, ping me and I'll email you).
> In the future, I will attempt to make rcutop built within the kernel repo.
> This is already done for another tool (see tools/bpf/runqslower) so is doable.
>
> The 2 mm patches are what Vlastimil pulled into slab-next. I included them in
> this series so that the tracing patch builds.
>
> Previous series was posted here:
> https://lore.kernel.org/all/20220713213237.1596225-1-joel@joelfernandes.org/
>
> Linked below [1] is some power data I collected with Turbostat on an x86
> ChromeOS ADL machine. The numbers are not based on -next, but rather 5.19
> kernel as that's what booted on my ChromeOS machine).
>
> These are output by Turbostat, by running:
> turbostat -S -s PkgWatt,CorWatt --interval 5
> PkgWatt - summary of package power in Watts 5 second interval.
> CoreWatt - summary of core power in Watts 5 second interval.
>
> [1] https://lore.kernel.org/r/b4145008-6840-fc69-a6d6-e38bc218009d@joelfernandes.org
Thank you for all your work on this!
I have pulled these in for testing and review. Some work is required
for them to be ready for mainline.
> Joel Fernandes (Google) (15):
I took these:
> rcu/tree: Use READ_ONCE() for lockless read of rnp->qsmask
> rcu: Fix late wakeup when flush of bypass cblist happens
> rcu: Move trace_rcu_callback() before bypassing
> rcu: Introduce call_rcu_lazy() API implementation
You and Frederic need to come to agreement on "rcu: Fix late wakeup when
flush of bypass cblist happens".
These have some difficulties, so I put them on top of the stack:
> rcu: Add per-CB tracing for queuing, flush and invocation.
This one breaks 32-bit MIPS.
> rcuscale: Add laziness and kfree tests
I am concerned that this one has OOM problems.
> rcutorture: Add test code for call_rcu_lazy()
This one does not need a separate scenario, but instead a separate
rcutorture.gp_lazy boot parameter. For a rough template for this
sort of change, please see the rcutorture changes in this commit:
76ea364161e7 ("rcu: Add full-sized polling for start_poll()")
The key point is that every rcutorture.torture_type=rcu test then
becomes a call_rcu_lazy() test. (Unless explicitly overridden.)
I took these, though they need go up their respective trees or get acks
from their respective maintainers.
> fs: Move call_rcu() to call_rcu_lazy() in some paths
> cred: Move call_rcu() to call_rcu_lazy()
> security: Move call_rcu() to call_rcu_lazy()
> net/core: Move call_rcu() to call_rcu_lazy()
> kernel: Move various core kernel usages to call_rcu_lazy()
> lib: Move call_rcu() to call_rcu_lazy()
> i915: Move call_rcu() to call_rcu_lazy()
> fork: Move thread_stack_free_rcu() to call_rcu_lazy()
>
> Vineeth Pillai (1):
I took this:
> rcu: shrinker for lazy rcu
>
> Vlastimil Babka (2):
As noted earlier, I took these strictly for testing. I do not expect
to push them into -next, let alone into mainline.
> mm/slub: perform free consistency checks before call_rcu
> mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head
These all are on -rcu not-yet-for-mainline branch lazy.2022.09.03b.
Thanx, Paul
> drivers/gpu/drm/i915/gem/i915_gem_object.c | 2 +-
> fs/dcache.c | 4 +-
> fs/eventpoll.c | 2 +-
> fs/file_table.c | 2 +-
> fs/inode.c | 2 +-
> include/linux/rcupdate.h | 6 +
> include/linux/types.h | 44 +++
> include/trace/events/rcu.h | 69 ++++-
> kernel/cred.c | 2 +-
> kernel/exit.c | 2 +-
> kernel/fork.c | 6 +-
> kernel/pid.c | 2 +-
> kernel/rcu/Kconfig | 19 ++
> kernel/rcu/rcu.h | 12 +
> kernel/rcu/rcu_segcblist.c | 23 +-
> kernel/rcu/rcu_segcblist.h | 8 +
> kernel/rcu/rcuscale.c | 74 ++++-
> kernel/rcu/rcutorture.c | 60 +++-
> kernel/rcu/tree.c | 187 ++++++++----
> kernel/rcu/tree.h | 13 +-
> kernel/rcu/tree_nocb.h | 282 +++++++++++++++---
> kernel/time/posix-timers.c | 2 +-
> lib/radix-tree.c | 2 +-
> lib/xarray.c | 2 +-
> mm/slab.h | 54 ++--
> mm/slub.c | 20 +-
> net/core/dst.c | 2 +-
> security/security.c | 2 +-
> security/selinux/avc.c | 4 +-
> .../selftests/rcutorture/configs/rcu/CFLIST | 1 +
> .../selftests/rcutorture/configs/rcu/TREE11 | 18 ++
> .../rcutorture/configs/rcu/TREE11.boot | 8 +
> 32 files changed, 783 insertions(+), 153 deletions(-)
> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/TREE11
> create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/TREE11.boot
>
> --
> 2.37.2.789.g6183377224-goog
>
prev parent reply other threads:[~2022-09-03 15:22 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 22:17 [PATCH v5 00/18] Implement call_rcu_lazy() and miscellaneous fixes Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 01/18] mm/slub: perform free consistency checks before call_rcu Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 02/18] mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head Joel Fernandes (Google)
2022-09-02 9:26 ` Vlastimil Babka
2022-09-02 9:30 ` Vlastimil Babka
2022-09-02 15:09 ` Joel Fernandes
2022-09-03 13:53 ` Paul E. McKenney
2022-09-01 22:17 ` [PATCH v5 03/18] rcu/tree: Use READ_ONCE() for lockless read of rnp->qsmask Joel Fernandes (Google)
2022-09-06 22:26 ` Boqun Feng
2022-09-06 22:31 ` Joel Fernandes
2022-09-01 22:17 ` [PATCH v5 04/18] rcu: Fix late wakeup when flush of bypass cblist happens Joel Fernandes (Google)
2022-09-02 11:35 ` Frederic Weisbecker
2022-09-02 23:58 ` Joel Fernandes
2022-09-03 15:10 ` Paul E. McKenney
2022-09-04 21:13 ` Frederic Weisbecker
2022-09-03 14:04 ` Paul E. McKenney
2022-09-03 14:05 ` Joel Fernandes
2022-09-06 3:07 ` Joel Fernandes
2022-09-06 9:48 ` Frederic Weisbecker
2022-09-07 2:43 ` Joel Fernandes
2022-09-01 22:17 ` [PATCH v5 05/18] rcu: Move trace_rcu_callback() before bypassing Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 06/18] rcu: Introduce call_rcu_lazy() API implementation Joel Fernandes (Google)
2022-09-02 15:21 ` Frederic Weisbecker
2022-09-02 23:09 ` Joel Fernandes
2022-09-05 12:59 ` Frederic Weisbecker
2022-09-05 20:18 ` Joel Fernandes
2022-09-05 20:32 ` Joel Fernandes
2022-09-06 8:55 ` Paul E. McKenney
2022-09-06 16:16 ` Joel Fernandes
2022-09-06 17:05 ` Paul E. McKenney
2022-09-03 22:00 ` Joel Fernandes
2022-09-04 21:01 ` Frederic Weisbecker
2022-09-05 20:20 ` Joel Fernandes
2022-09-06 3:05 ` Joel Fernandes
2022-09-06 15:17 ` Frederic Weisbecker
2022-09-06 16:15 ` Joel Fernandes
2022-09-06 16:31 ` Joel Fernandes
2022-09-06 16:38 ` Joel Fernandes
2022-09-06 16:43 ` Joel Fernandes
2022-09-06 19:11 ` Frederic Weisbecker
2022-09-07 2:56 ` Joel Fernandes
2022-09-07 9:56 ` Frederic Weisbecker
2022-09-07 10:03 ` Frederic Weisbecker
2022-09-07 14:01 ` Joel Fernandes
2022-09-07 0:06 ` Joel Fernandes
2022-09-07 9:40 ` Frederic Weisbecker
2022-09-07 13:44 ` Joel Fernandes
2022-09-07 15:38 ` Frederic Weisbecker
2022-09-07 15:39 ` Joel Fernandes
2022-09-21 23:52 ` Joel Fernandes
2022-09-06 18:16 ` Uladzislau Rezki
2022-09-06 18:21 ` Joel Fernandes
2022-09-07 8:52 ` Uladzislau Rezki
2022-09-07 15:23 ` Joel Fernandes
2022-09-03 14:03 ` Paul E. McKenney
2022-09-03 14:05 ` Joel Fernandes
2022-09-01 22:17 ` [PATCH v5 07/18] rcu: shrinker for lazy rcu Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 08/18] rcu: Add per-CB tracing for queuing, flush and invocation Joel Fernandes (Google)
2022-09-02 16:48 ` kernel test robot
2022-09-03 12:39 ` Paul E. McKenney
2022-09-03 14:07 ` Joel Fernandes
2022-09-02 19:01 ` kernel test robot
2022-09-01 22:17 ` [PATCH v5 09/18] rcuscale: Add laziness and kfree tests Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 10/18] rcutorture: Add test code for call_rcu_lazy() Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 11/18] fs: Move call_rcu() to call_rcu_lazy() in some paths Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 12/18] cred: Move call_rcu() to call_rcu_lazy() Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 13/18] security: " Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 14/18] net/core: " Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 15/18] kernel: Move various core kernel usages " Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 16/18] lib: Move call_rcu() " Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 17/18] i915: " Joel Fernandes (Google)
2022-09-01 22:17 ` [PATCH v5 18/18] fork: Move thread_stack_free_rcu() " Joel Fernandes (Google)
2022-09-03 15:22 ` Paul E. McKenney [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220903152242.GA870876@paulmck-ThinkPad-P17-Gen-1 \
--to=paulmck@kernel.org \
--cc=boqun.feng@gmail.com \
--cc=frederic@kernel.org \
--cc=joel@joelfernandes.org \
--cc=linux-kernel@vger.kernel.org \
--cc=neeraj.iitr10@gmail.com \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=rushikesh.s.kadam@intel.com \
--cc=urezki@gmail.com \
--cc=vineeth@bitbyteword.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).