Re: [PATCH bpf v2] powerpc/bpf: enforce full ordering for ATOMIC operations with BPF_FETCH

2024-05-08 Thread Paul E. McKenney
/\ 1:r7=0) > Observation SB+atomic_add+fetch Never 0 9 > > [1] https://www.kernel.org/doc/Documentation/memory-barriers.txt > [2] https://www.kernel.org/doc/Documentation/atomic_t.txt > > Fixes: 65112709115f ("powerpc/bpf/64: add support for BPF_ATOMIC bitwise > ope

Re: [PATCH RFC] rcu: torture: shorten the time between forward-progress tests

2023-08-23 Thread Paul E. McKenney
On Tue, May 02, 2023 at 11:06:02PM +0800, zhouzho...@gmail.com wrote: > From: Zhouyi Zhou > > Currently, default time between rcu torture forward-progress tests is 60HZ, > Under this configuration, false positive caused by __stack_chk_fail [1] is > difficult to reproduce (needs average 5*420

Re: [PATCH] rcu: torture: ppc: Remove duplicated argument --enable-kvm

2023-03-26 Thread Paul E. McKenney
On Sun, Mar 26, 2023 at 08:24:34AM +0800, zhouzho...@gmail.com wrote: > From: Zhouyi Zhou > > The argument --enable-kvm is duplicated because qemu_args > in kvm-test-1-run.sh has already give this. > > Signed-off-by: Zhouyi Zhou Good catch! Applied, thank you!

Re: [next-20230322] Kernel WARN at kernel/workqueue.c:3182 (rcutorture)

2023-03-23 Thread Paul E. McKenney
On Fri, Mar 24, 2023 at 08:47:38AM +0530, Sachin Sant wrote: > > >>> Hello, Sachin, and it looks like you hit something that Zqiang and I > >>> have been tracking down. I am guessing that you were using modprobe > >>> and rmmod to make this happen, and that this happened at rmmod time. > >>> >

Re: [next-20230322] Kernel WARN at kernel/workqueue.c:3182 (rcutorture)

2023-03-23 Thread Paul E. McKenney
On Thu, Mar 23, 2023 at 11:00:59PM +0530, Sachin Sant wrote: > > >> [ 3629.243407] NIP [7fff8cd39558] 0x7fff8cd39558 > >> [ 3629.243410] LR [00010d800398] 0x10d800398 > >> [ 3629.243413] --- interrupt: c00 > >> [ 3629.243415] Code: 419dffa4 e93a0078 3941 552907be 2f89 7d20579e >

Re: [next-20230322] Kernel WARN at kernel/workqueue.c:3182 (rcutorture)

2023-03-23 Thread Paul E. McKenney
On Thu, Mar 23, 2023 at 04:55:54PM +0530, Sachin Sant wrote: > While running rcutorture tests from LTP on an IBM Power10 server booted with > 6.3.0-rc3-next-20230322 following warning is observed: > > [ 3629.242831] [ cut here ] > [ 3629.242835] WARNING: CPU: 8 PID: 614614

Re: [PATCH v2] arch/powerpc/include/asm/barrier.h: redefine rmb and wmb to lwsync

2023-02-22 Thread Paul E. McKenney
On Thu, Feb 23, 2023 at 09:31:48AM +0530, Kautuk Consul wrote: > On 2023-02-22 09:47:19, Paul E. McKenney wrote: > > On Wed, Feb 22, 2023 at 02:33:44PM +0530, Kautuk Consul wrote: > > > A link from ibm.com states: > > > "Ensures that all instructions preceding the

Re: [PATCH v2] arch/powerpc/include/asm/barrier.h: redefine rmb and wmb to lwsync

2023-02-22 Thread Paul E. McKenney
On Wed, Feb 22, 2023 at 02:33:44PM +0530, Kautuk Consul wrote: > A link from ibm.com states: > "Ensures that all instructions preceding the call to __lwsync > complete before any subsequent store instructions can be executed > on the processor that executed the function. Also, it ensures that >

Re: [PATCH v2 00/24] cpu,sched: Mark arch_cpu_idle_dead() __noreturn

2023-02-15 Thread Paul E. McKenney
1: > - add __noreturn to all arch_cpu_idle_dead() implementations (mpe) With this, rcutorture no longer gets objtool complaints on x86, thank you! Tested-by: Paul E. McKenney > Josh Poimboeuf (24): > alpha/cpu: Expose arch_cpu_idle_dead()'s prototype declaration > alpha/cpu: Make

Re: [PATCH v3 1/7] kernel/fork: convert vma assignment to a memcpy

2023-01-26 Thread Paul E. McKenney
On Wed, Jan 25, 2023 at 05:34:49PM -0800, Andrew Morton wrote: > On Wed, 25 Jan 2023 16:50:01 -0800 Suren Baghdasaryan > wrote: > > > On Wed, Jan 25, 2023 at 4:22 PM Andrew Morton > > wrote: > > > > > > On Wed, 25 Jan 2023 15:35:48 -0800 Suren Baghdasaryan > > > wrote: > > > > > > > Convert

Re: [PATCH 39/41] kernel/fork: throttle call_rcu() calls in vm_area_free

2023-01-20 Thread Paul E. McKenney
On Fri, Jan 20, 2023 at 04:49:42PM +, Matthew Wilcox wrote: > On Fri, Jan 20, 2023 at 08:45:21AM -0800, Suren Baghdasaryan wrote: > > On Fri, Jan 20, 2023 at 8:20 AM Suren Baghdasaryan > > wrote: > > > > > > On Fri, Jan 20, 2023 at 12:52 AM Michal Hocko wrote: > > > > > > > > On Thu

Re: [PATCH 39/41] kernel/fork: throttle call_rcu() calls in vm_area_free

2023-01-20 Thread Paul E. McKenney
On Fri, Jan 20, 2023 at 09:57:05AM +0100, Michal Hocko wrote: > On Thu 19-01-23 11:17:07, Paul E. McKenney wrote: > > On Thu, Jan 19, 2023 at 01:52:14PM +0100, Michal Hocko wrote: > > > On Wed 18-01-23 11:01:08, Suren Baghdasaryan wrote: > > > > On Wed, Jan 18, 202

Re: [PATCH 39/41] kernel/fork: throttle call_rcu() calls in vm_area_free

2023-01-19 Thread Paul E. McKenney
On Thu, Jan 19, 2023 at 11:47:36AM -0800, Suren Baghdasaryan wrote: > On Thu, Jan 19, 2023 at 11:20 AM Paul E. McKenney wrote: > > > > On Thu, Jan 19, 2023 at 10:52:03AM -0800, Suren Baghdasaryan wrote: > > > On Thu, Jan 19, 2023 at 4:59 AM Michal Hocko wrote: > >

Re: [PATCH 39/41] kernel/fork: throttle call_rcu() calls in vm_area_free

2023-01-19 Thread Paul E. McKenney
On Thu, Jan 19, 2023 at 10:52:03AM -0800, Suren Baghdasaryan wrote: > On Thu, Jan 19, 2023 at 4:59 AM Michal Hocko wrote: > > > > On Mon 09-01-23 12:53:34, Suren Baghdasaryan wrote: > > > call_rcu() can take a long time when callback offloading is enabled. > > > Its use in the vm_area_free can

Re: [PATCH 39/41] kernel/fork: throttle call_rcu() calls in vm_area_free

2023-01-19 Thread Paul E. McKenney
On Thu, Jan 19, 2023 at 01:52:14PM +0100, Michal Hocko wrote: > On Wed 18-01-23 11:01:08, Suren Baghdasaryan wrote: > > On Wed, Jan 18, 2023 at 10:34 AM Paul E. McKenney > > wrote: > [...] > > > There are a couple of possibilities here. > > > > > > F

Re: [PATCH 39/41] kernel/fork: throttle call_rcu() calls in vm_area_free

2023-01-18 Thread Paul E. McKenney
On Wed, Jan 18, 2023 at 11:01:08AM -0800, Suren Baghdasaryan wrote: > On Wed, Jan 18, 2023 at 10:34 AM Paul E. McKenney wrote: > > > > On Wed, Jan 18, 2023 at 10:04:39AM -0800, Suren Baghdasaryan wrote: > > > On Wed, Jan 18, 2023 at 1:49 AM Michal Hocko wrote: > >

Re: [PATCH 39/41] kernel/fork: throttle call_rcu() calls in vm_area_free

2023-01-18 Thread Paul E. McKenney
On Wed, Jan 18, 2023 at 10:04:39AM -0800, Suren Baghdasaryan wrote: > On Wed, Jan 18, 2023 at 1:49 AM Michal Hocko wrote: > > > > On Tue 17-01-23 17:19:46, Suren Baghdasaryan wrote: > > > On Tue, Jan 17, 2023 at 7:57 AM Michal Hocko wrote: > > > > > > > > On Mon 09-01-23 12:53:34, Suren

Re: [PATCH v3 00/51] cpuidle,rcu: Clean up the mess

2023-01-13 Thread Paul E. McKenney
k has been prodding that with something sharp. > > The last version was tested by a number of people and I'm hoping to not have > broken anything in the meantime ;-) > > > Changes since v2: 150 rcutorture hours on each of the default scenarios passed. This is qemu/KVM

Re: [PATCH rcu 04/27] arch/powerpc/kvm: Remove "select SRCU"

2023-01-11 Thread Paul E. McKenney
On Thu, Jan 12, 2023 at 10:49:04AM +1100, Michael Ellerman wrote: > "Paul E. McKenney" writes: > > Now that the SRCU Kconfig option is unconditionally selected, there is > > no longer any point in selecting it. Therefore, remove the "select SRCU" > &g

[PATCH rcu 04/27] arch/powerpc/kvm: Remove "select SRCU"

2023-01-04 Thread Paul E. McKenney
Now that the SRCU Kconfig option is unconditionally selected, there is no longer any point in selecting it. Therefore, remove the "select SRCU" Kconfig statements. Signed-off-by: Paul E. McKenney Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: --- arch/powerpc/k

Re: [PATCH linux-next][RFC]torture: avoid offline tick_do_timer_cpu

2022-11-28 Thread Paul E. McKenney
On Mon, Nov 28, 2022 at 09:12:28AM +0100, Thomas Gleixner wrote: > On Sun, Nov 27 2022 at 09:53, Paul E. McKenney wrote: > > On Sun, Nov 27, 2022 at 01:40:28PM +0100, Thomas Gleixner wrote: > >> There are quite some reasons why a CPU-hotplug or a hot-unplug operation &g

Re: [PATCH linux-next][RFC]torture: avoid offline tick_do_timer_cpu

2022-11-27 Thread Paul E. McKenney
On Sun, Nov 27, 2022 at 01:40:28PM +0100, Thomas Gleixner wrote: [ . . . ] > >> No. We are not exporting this just to make a bogus test case happy. > >> > >> Fix the torture code to handle -EBUSY correctly. > > I am going to do a study on this, for now, I do a grep in the kernel tree: > > find .

Re: [PATCH linux-next][RFC]torture: avoid offline tick_do_timer_cpu

2022-11-23 Thread Paul E. McKenney
On Wed, Nov 23, 2022 at 11:25:43PM +0100, Frederic Weisbecker wrote: > On Mon, Nov 21, 2022 at 05:37:54PM -0800, Paul E. McKenney wrote: > > On Mon, Nov 21, 2022 at 11:51:40AM +0800, Zhouyi Zhou wrote: > > > @@ -358,7 +359,16 @@ tortu

Re: [PATCH linux-next][RFC]torture: avoid offline tick_do_timer_cpu

2022-11-23 Thread Paul E. McKenney
On Wed, Nov 23, 2022 at 10:23:11AM +0800, Zhouyi Zhou wrote: > On Tue, Nov 22, 2022 at 9:37 AM Paul E. McKenney wrote: > > > > On Mon, Nov 21, 2022 at 11:51:40AM +0800, Zhouyi Zhou wrote: > > > During CPU-hotplug torture (CONFIG_NO_HZ_FULL=y), if we try to > &g

Re: [PATCH linux-next][RFC]torture: avoid offline tick_do_timer_cpu

2022-11-21 Thread Paul E. McKenney
On Mon, Nov 21, 2022 at 11:51:40AM +0800, Zhouyi Zhou wrote: > During CPU-hotplug torture (CONFIG_NO_HZ_FULL=y), if we try to > offline tick_do_timer_cpu, the operation will fail because in > function tick_nohz_cpu_down: > ``` > if (tick_nohz_full_running && tick_do_timer_cpu == cpu) >

Re: [PATCH linux-next][RFC] powerpc: protect cpu offlining by RCU offline lock

2022-09-14 Thread Paul E. McKenney
On Wed, Sep 14, 2022 at 10:15:28AM +0800, Zhouyi Zhou wrote: > During the cpu offlining, the sub functions of xive_teardown_cpu will > call __lock_acquire when CONFIG_LOCKDEP=y. The latter function will > travel RCU protected list, so "WARNING: suspicious RCU usage" will be > triggered. > > Try

Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE

2022-07-30 Thread Paul E. McKenney
On Sat, Jul 30, 2022 at 02:40:32AM -0700, Michel Lespinasse wrote: > On Fri, Jul 29, 2022 at 08:26:22AM -0700, Paul E. McKenney wrote:> Would you > be willing to try another shot in the dark, but untested > > this time? I freely admit that this is

Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE

2022-07-29 Thread Paul E. McKenney
Or better yet, try the patch that Rafael proposed. ;-) Thanx, Paul On Fri, Jul 29, 2022 at 08:26:22AM -0700, Paul E. McKenney wrote: > On Fri, Jul 29, 2022 at 03:24:58AM -0700, Michel Lespinasse wrote: > > On Thu, Jul 28, 2022

Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE

2022-07-29 Thread Paul E. McKenney
On Fri, Jul 29, 2022 at 03:24:58AM -0700, Michel Lespinasse wrote: > On Thu, Jul 28, 2022 at 10:20:53AM -0700, Paul E. McKenney wrote: > > On Mon, Jul 25, 2022 at 12:43:06PM -0700, Michel Lespinasse wrote: > > > On Wed, Jun 08, 2022 at 04:27:27PM +0200, Peter Zijlstra wro

Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE

2022-07-28 Thread Paul E. McKenney
ry to build the kernel with CONFIG_RCU_EQS_DEBUG=y to enable equivalent debugging. Could you please try your test with the -rce commit shown below applied? Thanx, Paul ----

Re: [PATCH 16/36] rcu: Fix rcu_idle_exit()

2022-06-15 Thread Paul E. McKenney
t; can remove these calls. > > Signed-off-by: Peter Zijlstra (Intel) > Acked-by: Paul E. McKenney We have some fun conflicts between this series and Frederic's context-tracking series. But it looks like these can be resolved by: 1. A patch on top of Frederic's series that prov

Re: [PATCH v4] locking/csd_lock: change csdlock_debug from early_param to __setup

2022-05-27 Thread Paul E. McKenney
On Fri, May 27, 2022 at 02:49:03PM +0800, Chen Zhongjin wrote: > Hi, > > On 2022/5/18 9:11, Paul E. McKenney wrote: > > On Tue, May 17, 2022 at 11:22:04AM +0800, Chen Zhongjin wrote: > >> On 2022/5/10 17:46, Chen Zhongjin wrote: > >>> csdlock_debug uses

Re: [PATCH v4] locking/csd_lock: change csdlock_debug from early_param to __setup

2022-05-17 Thread Paul E. McKenney
On Tue, May 17, 2022 at 11:22:04AM +0800, Chen Zhongjin wrote: > On 2022/5/10 17:46, Chen Zhongjin wrote: > > csdlock_debug uses early_param and static_branch_enable() to enable > > csd_lock_wait feature, which triggers a panic on arm64 with config: > > CONFIG_SPARSEMEM=y > >

Re: [PATCH 20/30] panic: Add the panic informational notifier list

2022-04-27 Thread Paul E. McKenney
en > Cc: Neeraj Upadhyay > Cc: Nicholas Piggin > Cc: Paul Mackerras > Cc: Suzuki K Poulose > Cc: Thierry Reding > Cc: Thomas Bogendoerfer > Signed-off-by: Guilherme G. Piccoli >From an RCU perspective: Acked-by: Paul E. McKenney > --- > arch/arm64/kernel/setup.c

Re: Low-res tick handler device not going to ONESHOT_STOPPED when tick is stopped (was: rcu_sched self-detected stall on CPU)

2022-04-14 Thread Paul E. McKenney
xcerpts from Michael Ellerman's message of April 9, 2022 12:42 am: > >> Michael Ellerman writes: > >>> "Paul E. McKenney" writes: > >>>> On Wed, Apr 06, 2022 at 05:31:10PM +0800, Zhouyi Zhou wrote: > >>>>> Hi > >>>&

Re: rcu_sched self-detected stall on CPU

2022-04-12 Thread Paul E. McKenney
On Tue, Apr 12, 2022 at 04:53:06PM +1000, Michael Ellerman wrote: > "Paul E. McKenney" writes: > > On Sun, Apr 10, 2022 at 09:33:43PM +1000, Michael Ellerman wrote: > >> Zhouyi Zhou writes: > >> > On Fri, Apr 8, 2022 at 10:07 PM Paul E. McKenney > >

Re: rcu_sched self-detected stall on CPU

2022-04-10 Thread Paul E. McKenney
On Sun, Apr 10, 2022 at 09:33:43PM +1000, Michael Ellerman wrote: > Zhouyi Zhou writes: > > On Fri, Apr 8, 2022 at 10:07 PM Paul E. McKenney wrote: > >> On Fri, Apr 08, 2022 at 06:02:19PM +0800, Zhouyi Zhou wrote: > >> > On Fri, Apr 8, 2022 at 3:23 PM M

Re: rcu_sched self-detected stall on CPU

2022-04-08 Thread Paul E. McKenney
On Sat, Apr 09, 2022 at 12:42:39AM +1000, Michael Ellerman wrote: > Michael Ellerman writes: > > "Paul E. McKenney" writes: > >> On Wed, Apr 06, 2022 at 05:31:10PM +0800, Zhouyi Zhou wrote: > >>> Hi > >>> > >>> I can reproduce

Re: rcu_sched self-detected stall on CPU

2022-04-08 Thread Paul E. McKenney
On Fri, Apr 08, 2022 at 06:02:19PM +0800, Zhouyi Zhou wrote: > On Fri, Apr 8, 2022 at 3:23 PM Michael Ellerman wrote: > > > > "Paul E. McKenney" writes: > > > On Wed, Apr 06, 2022 at 05:31:10PM +0800, Zhouyi Zhou wrote: > > >> Hi > > >&g

Re: rcu_sched self-detected stall on CPU

2022-04-08 Thread Paul E. McKenney
On Fri, Apr 08, 2022 at 05:23:32PM +1000, Michael Ellerman wrote: > "Paul E. McKenney" writes: > > On Wed, Apr 06, 2022 at 05:31:10PM +0800, Zhouyi Zhou wrote: > >> Hi > >> > >> I can reproduce it in a ppc virtual cloud server provided by Oregon

Re: rcu_sched self-detected stall on CPU

2022-04-07 Thread Paul E. McKenney
On Fri, Apr 08, 2022 at 07:14:20AM +0800, Zhouyi Zhou wrote: > Dear Paul and Miguel > > On Fri, Apr 8, 2022 at 1:55 AM Paul E. McKenney wrote: > > > > On Thu, Apr 07, 2022 at 07:05:58PM +0200, Miguel Ojeda wrote: > > > On Thu, Apr 7, 2022 at 5:15 PM

Re: rcu_sched self-detected stall on CPU

2022-04-07 Thread Paul E. McKenney
On Thu, Apr 07, 2022 at 07:05:58PM +0200, Miguel Ojeda wrote: > On Thu, Apr 7, 2022 at 5:15 PM Paul E. McKenney wrote: > > > > Ah. So you would instead look for boot to have completed within 10 > > seconds? Either way, reliable automation might well more important than

Re: rcu_sched self-detected stall on CPU

2022-04-07 Thread Paul E. McKenney
On Thu, Apr 07, 2022 at 12:07:34PM +0200, Miguel Ojeda wrote: > On Thu, Apr 7, 2022 at 4:27 AM Zhouyi Zhou wrote: > > > > Yes, this happens within 30 seconds after kernel boot. If we take all > > into account (qemu preparing, kernel loading), we can do one test > > within 54 seconds. > > When

Re: rcu_sched self-detected stall on CPU

2022-04-06 Thread Paul E. McKenney
On Thu, Apr 07, 2022 at 02:25:59AM +0800, Zhouyi Zhou wrote: > Hi Paul > > On Thu, Apr 7, 2022 at 1:00 AM Paul E. McKenney wrote: > > > > On Wed, Apr 06, 2022 at 05:31:10PM +0800, Zhouyi Zhou wrote: > > > Hi > > > > > > I can reproduce it

Re: rcu_sched self-detected stall on CPU

2022-04-06 Thread Paul E. McKenney
On Wed, Apr 06, 2022 at 05:31:10PM +0800, Zhouyi Zhou wrote: > Hi > > I can reproduce it in a ppc virtual cloud server provided by Oregon > State University. Following is what I do: > 1) curl -l > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/snapshot/linux-5.18-rc1.tar.gz

Re: rcutorture’s init segfaults in ppc64le VM

2022-03-09 Thread Paul E. McKenney
On Thu, Mar 10, 2022 at 10:37:12AM +0800, Zhouyi Zhou wrote: > Dear Paul > > I try to reproduce the bug in ppc64 VM in Oregon State University > using the vmlinux extracted from > https://owww.molgen.mpg.de/~pmenzel/rcutorture-2022.02.01-21.52.37-torture-locktorture-kasan-lock01.tar.xz > > the

Re: ppc64le: rcutorture warns about improperly set `CONFIG_HYPERVISOR_GUEST` and `CONFIG_PARAVIRT`

2022-02-07 Thread Paul E. McKenney
On Mon, Feb 07, 2022 at 05:53:05PM +0100, Paul Menzel wrote: > Dear Sebastian, dear Paul, > > > In commit a6fda6dab9 (rcutorture: Tweak kvm options) > `tools/testing/selftests/rcutorture/configs/rcu/CFcommon` was extended by > the three selections below: > > CONFIG_HYPERVISOR_GUEST=y >

Re: rcutorture’s init segfaults in ppc64le VM

2022-02-07 Thread Paul E. McKenney
On Mon, Feb 07, 2022 at 05:44:47PM +0100, Paul Menzel wrote: > Dear Linux folks, > > > On the POWER8 server IBM S822LC running Ubuntu 21.10, building Linux > 5.17-rc2+ with rcutorture tests > > $ tools/testing/selftests/rcutorture/bin/torture.sh --duration 10 > > the built init > > $

Re: ftrace hangs waiting for rcu

2022-01-28 Thread Paul E. McKenney
On Fri, Jan 28, 2022 at 08:15:47AM -0800, Paul E. McKenney wrote: > On Fri, Jan 28, 2022 at 04:11:57PM +, Mark Rutland wrote: > > On Fri, Jan 28, 2022 at 05:08:48PM +0100, Sven Schnelle wrote: > > > Hi Mark, > > > > > > Mark Rutland writes: > >

Re: ftrace hangs waiting for rcu

2022-01-28 Thread Paul E. McKenney
On Fri, Jan 28, 2022 at 04:11:57PM +, Mark Rutland wrote: > On Fri, Jan 28, 2022 at 05:08:48PM +0100, Sven Schnelle wrote: > > Hi Mark, > > > > Mark Rutland writes: > > > > > On arm64 I bisected this down to: > > > > > > 7a30871b6a27de1a ("rcu-tasks: Introduce ->percpu_enqueue_shift for

[GIT PULL] Fix kprobes issue by moving RCU-tasks initialization earlier

2021-01-04 Thread Paul E. McKenney
Hello, Linus, This fix is for a regression in the v5.10 merge window, but it was reported quite late in the v5.10 process, plus generating and testing the fix took some time. The regression is due to 36dadef23fcc ("kprobes: Init kprobes in early_initcall") which on powerpc can use RCU Tasks

Re: powerpc 5.10-rcN boot failures with RCU_SCALE_TEST=m

2020-11-27 Thread Paul E. McKenney
On Fri, Nov 27, 2020 at 01:02:29PM +1100, Daniel Axtens wrote: > Hi all, > > I'm having some difficulty tracking down a bug. > > Some configurations of the powerpc kernel since somewhere in the 5.10 > merge window fail to boot on some ppc64 systems. They hang while trying > to bring up SMP. It

Re: [PATCH] powerpc/smp: Move rcu_cpu_starting() earlier

2020-10-28 Thread Paul E. McKenney
On Thu, Oct 29, 2020 at 11:09:07AM +1100, Michael Ellerman wrote: > Qian Cai writes: > > The call to rcu_cpu_starting() in start_secondary() is not early enough > > in the CPU-hotplug onlining process, which results in lockdep splats as > > follows: > > Since when? > What kernel version? > > I

Re: [PATCH] powerpc/smp: Move rcu_cpu_starting() earlier

2020-10-28 Thread Paul E. McKenney
declared the CPU to be watched for readers. > > Link: > https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/ > Signed-off-by: Qian Cai Acked-by: Paul E. McKenney > --- > arch/powerpc/kernel/smp.c | 3 ++- > 1 file changed, 2 insertions(+)

Re: linux-next: manual merge of the rcu tree with the powerpc tree

2020-05-21 Thread Paul E. McKenney
On Thu, May 21, 2020 at 02:51:24PM +1000, Stephen Rothwell wrote: > Hi all, > > On Tue, 19 May 2020 17:23:16 +1000 Stephen Rothwell > wrote: > > > > Today's linux-next merge of the rcu tree got a conflict in: > > > > arch/powerpc/kernel/traps.c > > > > between commit: > > > >

Re: [PATCH 03/35] docs: fix broken references to text files

2020-04-08 Thread Paul E. McKenney
irier # > hwtracing/coresight/Kconfig > Signed-off-by: Mauro Carvalho Chehab For the memory-barrier.txt portions: Reviewed-by: Paul E. McKenney > --- > Documentation/memory-barriers.txt| 2 +- > Documentation/process/submit-checklist.rst | 2 +- >

Re: [PATCH v2] sched/core: fix illegal RCU from offline CPUs

2020-04-02 Thread Paul E. McKenney
On Thu, Apr 02, 2020 at 12:19:54PM -0400, Qian Cai wrote: > > > > On Apr 2, 2020, at 11:54 AM, Paul E. McKenney wrote: > > > > I do run this combination quite frequently, but only as part of > > rcutorture, which might not be a representative workload. For o

Re: [PATCH v2] sched/core: fix illegal RCU from offline CPUs

2020-04-02 Thread Paul E. McKenney
On Thu, Apr 02, 2020 at 10:00:16AM -0400, Qian Cai wrote: > > > > On Apr 2, 2020, at 7:24 AM, Michael Ellerman wrote: > > > > Qian Cai writes: > >> From: Peter Zijlstra > >> > >> In the CPU-offline process, it calls mmdrop() after idle entry and the > >> subsequent call to

Re: [PATCH v2] Documentation/locking/locktypes: minor copy editor fixes

2020-03-25 Thread Paul E. McKenney
onym and not part of a function name > > Signed-off-by: Randy Dunlap > Cc: Paul McKenney > Cc: Thomas Gleixner > Cc: Sebastian Siewior > Cc: Joel Fernandes > Cc: Ingo Molnar > Cc: Peter Zijlstra Some nits below, but with or without those suggested changes: Reviewe

Re: Documentation/locking/locktypes: Further clarifications and wordsmithing

2020-03-25 Thread Paul E. McKenney
On Wed, Mar 25, 2020 at 05:02:12PM +0100, Sebastian Siewior wrote: > On 2020-03-25 13:27:49 [+0100], Thomas Gleixner wrote: > > The documentation of rw_semaphores is wrong as it claims that the non-owner > > reader release is not supported by RT. That's just history biased memory > > distortion. >

Re: [patch V3 13/20] Documentation: Add lock ordering and nesting documentation

2020-03-24 Thread Paul E. McKenney
On Wed, Mar 25, 2020 at 12:13:34AM +0100, Thomas Gleixner wrote: > Paul, > > "Paul E. McKenney" writes: > > On Sat, Mar 21, 2020 at 12:25:57PM +0100, Thomas Gleixner wrote: > > In the normal case where the task sleeps through the entire lock > > acquisition,

Re: [PATCH v4 01/17] cpu: Add new {add,remove}_cpu() functions

2020-03-23 Thread Paul E. McKenney
Suggested-by: "Paul E. McKenney" > Signed-off-by: Qais Yousef > CC: Thomas Gleixner > CC: "Paul E. McKenney" Reviewed-by: Paul E. McKenney > CC: Helge Deller > CC: Michael Ellerman > CC: "David S. Miller" > CC: Juergen Gross > CC: Mark Rutland

Re: [patch V3 13/20] Documentation: Add lock ordering and nesting documentation

2020-03-22 Thread Paul E. McKenney
initial documentation. > > Signed-off-by: Thomas Gleixner > Cc: "Paul E . McKenney" > Cc: Jonathan Corbet > Cc: Davidlohr Bueso > Cc: Randy Dunlap > --- > V3: Addressed review comments from Paul, Jonathan, Davidlohr > V2: Addressed review comments from

Re: [patch V2 08/15] Documentation: Add lock ordering and nesting documentation

2020-03-21 Thread Paul E. McKenney
On Sat, Mar 21, 2020 at 11:26:06AM +0100, Thomas Gleixner wrote: > "Paul E. McKenney" writes: > > On Fri, Mar 20, 2020 at 11:36:03PM +0100, Thomas Gleixner wrote: > >> I agree that what I tried to express is hard to parse, but it's at least > >>

Re: [patch V2 08/15] Documentation: Add lock ordering and nesting documentation

2020-03-20 Thread Paul E. McKenney
On Fri, Mar 20, 2020 at 11:36:03PM +0100, Thomas Gleixner wrote: > "Paul E. McKenney" writes: > > On Fri, Mar 20, 2020 at 08:51:44PM +0100, Thomas Gleixner wrote: > >> "Paul E. McKenney" writes: > >> > > >> > - The soft interrupt re

Re: [patch V2 08/15] Documentation: Add lock ordering and nesting documentation

2020-03-20 Thread Paul E. McKenney
On Fri, Mar 20, 2020 at 08:51:44PM +0100, Thomas Gleixner wrote: > "Paul E. McKenney" writes: > > > > - The soft interrupt related suffix (_bh()) still disables softirq > >handlers. However, unlike non-PREEMPT_RT kernels (which disable > >preem

Re: [patch V2 08/15] Documentation: Add lock ordering and nesting documentation

2020-03-20 Thread Paul E. McKenney
On Thu, Mar 19, 2020 at 07:02:17PM +0100, Thomas Gleixner wrote: > Paul, > > "Paul E. McKenney" writes: > > > On Wed, Mar 18, 2020 at 09:43:10PM +0100, Thomas Gleixner wrote: > > > > Mostly native-English-speaker services below, so please feel f

Re: [patch V2 08/15] Documentation: Add lock ordering and nesting documentation

2020-03-18 Thread Paul E. McKenney
On Wed, Mar 18, 2020 at 09:43:10PM +0100, Thomas Gleixner wrote: > From: Thomas Gleixner > > The kernel provides a variety of locking primitives. The nesting of these > lock types and the implications of them on RT enabled kernels is nowhere > documented. > > Add initial documentation. > >

Re: [PATCH] treewide: Rename rcu_dereference_raw_notrace to _check

2019-07-12 Thread Paul E. McKenney
trace(). This patches renames all of them to be rcu_dereference_raw_check() with the "_check()" indicating sparse checking. Signed-off-by: Joel Fernandes (Google) [ paulmck: Fix checkpatch warnings about parentheses. ] Signed-off-by: Paul E. McKenney dif

Re: [PATCH RFC 0/5] Remove some notrace RCU APIs

2019-05-28 Thread Paul E. McKenney
On Tue, May 28, 2019 at 03:00:07PM -0400, Joel Fernandes wrote: > On Tue, May 28, 2019 at 05:24:47AM -0700, Paul E. McKenney wrote: > > On Sat, May 25, 2019 at 02:14:07PM -0400, Joel Fernandes wrote: > > > On Sat, May 25, 2019 at 08:50:35AM -0700, Paul E. McKenney wrote: >

Re: [PATCH RFC 0/5] Remove some notrace RCU APIs

2019-05-28 Thread Paul E. McKenney
On Sat, May 25, 2019 at 02:14:07PM -0400, Joel Fernandes wrote: > On Sat, May 25, 2019 at 08:50:35AM -0700, Paul E. McKenney wrote: > > On Sat, May 25, 2019 at 10:19:54AM -0400, Joel Fernandes wrote: > > > On Sat, May 25, 2019 at 07:08:26AM -0400, Steven Rostedt wrote: > >

Re: [PATCH RFC 0/5] Remove some notrace RCU APIs

2019-05-25 Thread Paul E. McKenney
On Sat, May 25, 2019 at 10:19:54AM -0400, Joel Fernandes wrote: > On Sat, May 25, 2019 at 07:08:26AM -0400, Steven Rostedt wrote: > > On Sat, 25 May 2019 04:14:44 -0400 > > Joel Fernandes wrote: > > > > > > I guess the difference between the _raw_notrace and just _raw variants > > > > is that

Re: [PATCH] MAINTAINERS: Update remaining @linux.vnet.ibm.com addresses

2019-04-11 Thread Paul E. McKenney
On Thu, Apr 11, 2019 at 05:27:31AM -0700, Joe Perches wrote: > On Thu, 2019-04-11 at 22:07 +1000, Michael Ellerman wrote: > > Joe Perches writes: > > > On Thu, 2019-04-11 at 06:27 +0200, Lukas Bulwahn wrote: > > > > Paul McKenney attempted to update all email addresses > > > >

Re: [PATCH] MAINTAINERS: Update remaining @linux.vnet.ibm.com addresses

2019-04-11 Thread Paul E. McKenney
mained. > > We update the remaining email addresses in MAINTAINERS, hopefully finally > catching all cases for good. > > Fixes: 1dfddcdb95c4 ("MAINTAINERS: Update from @linux.vnet.ibm.com to > @linux.ibm.com") > Signed-off-by: Lukas Bulwahn For whatever it is worth:

Re: [RFC PATCH v2 09/14] watchdog/hardlockup: Make arch_touch_nmi_watchdog() to hpet-based implementation

2019-02-27 Thread Paul E. McKenney
: Paul Mackerras > Cc: Mathieu Desnoyers > Cc: Masami Hiramatsu > Cc: Peter Zijlstra > Cc: Andrew Morton > Cc: Philippe Ombredanne > Cc: Colin Ian King > Cc: Byungchul Park > Cc: "Paul E. McKenney" > Cc: "Luis R. Rodriguez" > Cc: Waiman Long

[tip:core/rcu] powerpc: Convert hugepd_free() to use call_rcu()

2018-12-04 Thread tip-bot for Paul E. McKenney
Commit-ID: 04229110adfba984950fc0209632640a76eb1de4 Gitweb: https://git.kernel.org/tip/04229110adfba984950fc0209632640a76eb1de4 Author: Paul E. McKenney AuthorDate: Mon, 5 Nov 2018 16:53:13 -0800 Committer: Paul E. McKenney CommitDate: Thu, 8 Nov 2018 21:43:20 -0800 powerpc: Convert

Re: UBSAN: Undefined behaviour in kernel/rcu/tree_plugin.h in 4.20-rc1

2018-11-14 Thread Paul E. McKenney
On Wed, Nov 14, 2018 at 03:43:05PM +0100, Christophe LEROY wrote: > > > Le 09/11/2018 à 21:10, Paul E. McKenney a écrit : > >On Fri, Nov 09, 2018 at 06:11:20PM +0100, Christophe LEROY wrote: > >>(Resending due to error in Paul's address) > >> > >>Paul

[PATCH tip/core/rcu 08/41] powerpc: Convert hugepd_free() to use call_rcu()

2018-11-11 Thread Paul E. McKenney
Now that call_rcu()'s callback is not invoked until after all preempt-disable regions of code have completed (in addition to explicitly marked RCU read-side critical sections), call_rcu() can be used in place of call_rcu_sched(). This commit therefore makes that change. Signed-off-by: Paul E

Re: UBSAN: Undefined behaviour in kernel/rcu/tree_plugin.h in 4.20-rc1

2018-11-10 Thread Paul E. McKenney
On Fri, Nov 09, 2018 at 12:10:30PM -0800, Paul E. McKenney wrote: > On Fri, Nov 09, 2018 at 06:11:20PM +0100, Christophe LEROY wrote: > > (Resending due to error in Paul's address) > > > > Paul > > > > I get the following UBSAN reports in 4.20-rc1 on a

Re: UBSAN: Undefined behaviour in kernel/rcu/tree_plugin.h in 4.20-rc1

2018-11-09 Thread Paul E. McKenney
On Fri, Nov 09, 2018 at 06:11:20PM +0100, Christophe LEROY wrote: > (Resending due to error in Paul's address) > > Paul > > I get the following UBSAN reports in 4.20-rc1 on an MPC8321E > (powerpc/book3s/32) > > I bisected it to 3e31009898699dfc ("rcu: Defer reporting RCU-preempt > quiescent

Re: [RFC PATCH] lib: Introduce generic __cmpxchg_u64() and use it where needed

2018-11-02 Thread Paul E. McKenney
On Fri, Nov 02, 2018 at 01:23:28PM +0100, Peter Zijlstra wrote: > On Fri, Nov 02, 2018 at 10:56:31AM +, David Laight wrote: > > From: Paul E. McKenney > > > Sent: 01 November 2018 17:02 > > ... > > > And there is a push to define C++ s

Re: [RFC PATCH] lib: Introduce generic __cmpxchg_u64() and use it where needed

2018-11-02 Thread Paul E. McKenney
On Fri, Nov 02, 2018 at 10:56:31AM +, David Laight wrote: > From: Paul E. McKenney > > Sent: 01 November 2018 17:02 > ... > > And there is a push to define C++ signed arithmetic as 2s complement, > > but there are still 1s complement systems with C compilers. Ju

Re: [RFC PATCH] lib: Introduce generic __cmpxchg_u64() and use it where needed

2018-11-01 Thread Paul E. McKenney
On Thu, Nov 01, 2018 at 10:38:34PM +0100, Peter Zijlstra wrote: > On Thu, Nov 01, 2018 at 01:29:10PM -0700, Paul E. McKenney wrote: > > On Thu, Nov 01, 2018 at 06:27:39PM +0100, Peter Zijlstra wrote: > > > On Thu, Nov 01, 2018 at 06:14:32PM +0100, Peter Zijlstra wrote: > &g

Re: [RFC PATCH] lib: Introduce generic __cmpxchg_u64() and use it where needed

2018-11-01 Thread Paul E. McKenney
On Thu, Nov 01, 2018 at 06:27:39PM +0100, Peter Zijlstra wrote: > On Thu, Nov 01, 2018 at 06:14:32PM +0100, Peter Zijlstra wrote: > > > This reminds me of this so silly patch :/ > > > > > >

Re: [RFC PATCH] lib: Introduce generic __cmpxchg_u64() and use it where needed

2018-11-01 Thread Paul E. McKenney
On Thu, Nov 01, 2018 at 06:14:32PM +0100, Peter Zijlstra wrote: > On Thu, Nov 01, 2018 at 09:59:38AM -0700, Eric Dumazet wrote: > > On 11/01/2018 09:32 AM, Peter Zijlstra wrote: > > > > >> Anyhow, if the atomic maintainers are willing to stand up and state for > > >> the record that the atomic

Re: [RFC PATCH] lib: Introduce generic __cmpxchg_u64() and use it where needed

2018-11-01 Thread Paul E. McKenney
On Thu, Nov 01, 2018 at 06:18:46PM +0100, Peter Zijlstra wrote: > On Thu, Nov 01, 2018 at 10:01:46AM -0700, Paul E. McKenney wrote: > > On Thu, Nov 01, 2018 at 05:32:12PM +0100, Peter Zijlstra wrote: > > > On Thu, Nov 01, 2018 at 03:22:15PM +, Trond Myklebust wrote: > >

Re: [RFC PATCH] lib: Introduce generic __cmpxchg_u64() and use it where needed

2018-11-01 Thread Paul E. McKenney
On Thu, Nov 01, 2018 at 05:32:12PM +0100, Peter Zijlstra wrote: > On Thu, Nov 01, 2018 at 03:22:15PM +, Trond Myklebust wrote: > > On Thu, 2018-11-01 at 15:59 +0100, Peter Zijlstra wrote: > > > On Thu, Nov 01, 2018 at 01:18:46PM +, Mark Rutland wrote: > > > > > > My one question (and the

Re: [PATCH] [RFC v2] Drop all 00-INDEX files from Documentation/

2018-09-04 Thread Paul E. McKenney
, but I rather not > if we just want to delete them anyway. > > As a starting point, remove all index-files and references to 00-INDEX and > see where the discussion is going. For the RCU portions: Acked-by: Paul E. McKenney > Again, sorry for the insanely wide distribution. &

Re: [PATCH 07/14] powerpc: Add support for restartable sequences

2018-05-23 Thread Paul E. McKenney
On Wed, May 23, 2018 at 04:14:39PM -0400, Mathieu Desnoyers wrote: > - On May 20, 2018, at 10:08 AM, Boqun Feng boqun.f...@gmail.com wrote: > > > On Fri, May 18, 2018 at 02:17:17PM -0400, Mathieu Desnoyers wrote: > >> - On May 17, 2018, at 7:50 PM, Boqun Feng boqun.f...@gmail.com wrote: >

Re: [PATCH 2/2] smp: introduce kick_active_cpus_sync()

2018-04-01 Thread Paul E. McKenney
On Sun, Apr 01, 2018 at 02:11:08PM +0300, Yury Norov wrote: > On Tue, Mar 27, 2018 at 11:21:17AM +0100, Will Deacon wrote: > > On Sun, Mar 25, 2018 at 08:50:04PM +0300, Yury Norov wrote: > > > kick_all_cpus_sync() forces all CPUs to sync caches by sending broadcast > > > IPI. > > > If CPU is in

Re: [PATCH 2/2] smp: introduce kick_active_cpus_sync()

2018-03-28 Thread Paul E. McKenney
On Wed, Mar 28, 2018 at 04:36:05PM +0300, Yury Norov wrote: > On Mon, Mar 26, 2018 at 05:45:55AM -0700, Paul E. McKenney wrote: > > On Sun, Mar 25, 2018 at 11:11:54PM +0300, Yury Norov wrote: > > > On Sun, Mar 25, 2018 at 12:23:28PM -0700, Paul E. McKenney wrote: > > > &

Re: [PATCH 2/2] smp: introduce kick_active_cpus_sync()

2018-03-28 Thread Paul E. McKenney
On Wed, Mar 28, 2018 at 05:41:40PM +0300, Yury Norov wrote: > On Wed, Mar 28, 2018 at 06:56:17AM -0700, Paul E. McKenney wrote: > > On Wed, Mar 28, 2018 at 04:36:05PM +0300, Yury Norov wrote: > > > On Mon, Mar 26, 2018 at 05:45:55AM -0700, Paul E. McKenney wrote: > > > &

Re: [PATCH 2/2] smp: introduce kick_active_cpus_sync()

2018-03-26 Thread Paul E. McKenney
On Sun, Mar 25, 2018 at 11:11:54PM +0300, Yury Norov wrote: > On Sun, Mar 25, 2018 at 12:23:28PM -0700, Paul E. McKenney wrote: > > On Sun, Mar 25, 2018 at 08:50:04PM +0300, Yury Norov wrote: > > > kick_all_cpus_sync() forces all CPUs to sync caches by sending broadcast >

Re: [PATCH 2/2] smp: introduce kick_active_cpus_sync()

2018-03-25 Thread Paul E. McKenney
On Sun, Mar 25, 2018 at 08:50:04PM +0300, Yury Norov wrote: > kick_all_cpus_sync() forces all CPUs to sync caches by sending broadcast IPI. > If CPU is in extended quiescent state (idle task or nohz_full userspace), this > work may be done at the exit of this state. Delaying synchronization helps

Re: [PATCH 1/2] rcu: declare rcu_eqs_special_set() in public header

2018-03-25 Thread Paul E. McKenney
to include/linux/rcutree.h, which allows it to be used in non-rcu kernel code. Signed-off-by: Yury Norov <yno...@caviumnetworks.com> Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com> diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index fd996cdf1

[PATCH tip/sched/membarrier 5/5] Fix: membarrier: Handle CLONE_VM + !CLONE_THREAD correctly on powerpc

2017-10-13 Thread Paul E. McKenney
f-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com> CC: Paul E. McKenney <paul...@linux.vnet.ibm.com> CC: Boqun Feng <boqun.f...@gmail.com> CC: Andrew Hunter <a...@google.com> CC: Maged Michael <maged.mich...@gmail.com> CC: gro...@google.com CC: Avi Kiv

[PATCH tip/sched/membarrier 1/5] membarrier: Provide register expedited private command

2017-10-13 Thread Paul E. McKenney
Desnoyers <mathieu.desnoy...@efficios.com> CC: Peter Zijlstra <pet...@infradead.org> CC: Paul E. McKenney <paul...@linux.vnet.ibm.com> CC: Boqun Feng <boqun.f...@gmail.com> CC: Andrew Hunter <a...@google.com> CC: Maged Michael <maged.mich...@gmail.com> CC: gro...@goo

[PATCH tip/sched/membarrier 4/5] membarrier: Remove unused code for architectures without membarrier hooks

2017-10-13 Thread Paul E. McKenney
tch_mm() for architectures with membarrier hooks. Reported-by: Nicholas Piggin <npig...@gmail.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com> CC: Peter Zijlstra <pet...@infradead.org> CC: Paul E. McKenney <paul...@linux.vnet.ibm.com> CC: Boqun Feng <boqun.

Re: [RFC PATCH for 4.14 1/2] membarrier: Remove unused code for architectures without membarrier hooks

2017-10-06 Thread Paul E. McKenney
lease let me know if you need it sooner. Thanx, Paul > CC: Peter Zijlstra <pet...@infradead.org> > CC: Paul E. McKenney <paul...@linux.vnet.ibm.com> > CC: Boqun Feng <boqun.f...@gmail.com> > CC: Andrew Hunter <a...@google.com> >

[PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

2017-10-04 Thread Paul E. McKenney
Desnoyers <mathieu.desnoy...@efficios.com> CC: Peter Zijlstra <pet...@infradead.org> CC: Paul E. McKenney <paul...@linux.vnet.ibm.com> CC: Boqun Feng <boqun.f...@gmail.com> CC: Andrew Hunter <a...@google.com> CC: Maged Michael <maged.mich...@gmail.com> CC: gro...@goo

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