* [PATCH 0/7] rcu: cleanups @ 2019-10-15 10:23 Lai Jiangshan 2019-10-15 10:23 ` [PATCH 1/7] rcu: fix incorrect conditional compilation Lai Jiangshan 2019-10-15 10:23 ` [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs Lai Jiangshan 0 siblings, 2 replies; 7+ messages in thread From: Lai Jiangshan @ 2019-10-15 10:23 UTC (permalink / raw) To: linux-kernel Cc: Lai Jiangshan, Paul E. McKenney, Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan, Joel Fernandes, rcu All are minimal independent cleanups, expect that patch 3 depends on patch 2. Lai Jiangshan (7): rcu: fix incorrect conditional compilation rcu: fix tracepoint string when RCU CPU kthread runs rcu: trace_rcu_utilization() paired rcu: remove the declaration of call_rcu() in tree.h rcu: move gp_state_names[] and gp_state_getname() to tree_stall.h rcu: rename some CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU rcu: splite tasks_rcu to tasks.c kernel/rcu/Makefile | 1 + kernel/rcu/rcu.h | 4 +- kernel/rcu/tasks.c | 395 +++++++++++++++++++++++++++++++++++++++ kernel/rcu/tree.c | 19 +- kernel/rcu/tree.h | 15 +- kernel/rcu/tree_plugin.h | 1 + kernel/rcu/tree_stall.h | 28 ++- kernel/rcu/update.c | 365 ------------------------------------ 8 files changed, 431 insertions(+), 397 deletions(-) create mode 100644 kernel/rcu/tasks.c -- 2.20.1 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/7] rcu: fix incorrect conditional compilation 2019-10-15 10:23 [PATCH 0/7] rcu: cleanups Lai Jiangshan @ 2019-10-15 10:23 ` Lai Jiangshan 2019-10-16 3:35 ` Paul E. McKenney 2019-10-15 10:23 ` [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs Lai Jiangshan 1 sibling, 1 reply; 7+ messages in thread From: Lai Jiangshan @ 2019-10-15 10:23 UTC (permalink / raw) To: linux-kernel Cc: Lai Jiangshan, Lai Jiangshan, Paul E. McKenney, Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Joel Fernandes, rcu DO NOT pick it to stable tree. (Since the title has "fix", this statement may help stop AI pick it to stable tree) The tokens SRCU and TINY_RCU are not defined by any configurations, they should be CONFIG_SRCU and CONFIG_TINY_RCU. But there is no harm when "TINY_RCU" is wrongly used, which are always non-defined, which makes "!defined(TINY_RCU)" always true, which means the code block is always inclued, and the included code block doesn't cause any compilation error so far when CONFIG_TINY_RCU. It is also the reason this change doesn't need for stable. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> --- kernel/rcu/rcu.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index a7ab2a023dd3..05f936ed167a 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -254,7 +254,7 @@ void rcu_test_sync_prims(void); */ extern void resched_cpu(int cpu); -#if defined(SRCU) || !defined(TINY_RCU) +#if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) #include <linux/rcu_node_tree.h> @@ -391,7 +391,7 @@ do { \ #define raw_lockdep_assert_held_rcu_node(p) \ lockdep_assert_held(&ACCESS_PRIVATE(p, lock)) -#endif /* #if defined(SRCU) || !defined(TINY_RCU) */ +#endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */ #ifdef CONFIG_SRCU void srcu_init(void); -- 2.20.1 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 1/7] rcu: fix incorrect conditional compilation 2019-10-15 10:23 ` [PATCH 1/7] rcu: fix incorrect conditional compilation Lai Jiangshan @ 2019-10-16 3:35 ` Paul E. McKenney 0 siblings, 0 replies; 7+ messages in thread From: Paul E. McKenney @ 2019-10-16 3:35 UTC (permalink / raw) To: Lai Jiangshan Cc: linux-kernel, Lai Jiangshan, Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Joel Fernandes, rcu On Tue, Oct 15, 2019 at 10:23:56AM +0000, Lai Jiangshan wrote: > DO NOT pick it to stable tree. > (Since the title has "fix", this statement may help stop > AI pick it to stable tree) > > The tokens SRCU and TINY_RCU are not defined by any configurations, > they should be CONFIG_SRCU and CONFIG_TINY_RCU. But there is no > harm when "TINY_RCU" is wrongly used, which are always non-defined, > which makes "!defined(TINY_RCU)" always true, which means > the code block is always inclued, and the included code block > doesn't cause any compilation error so far when CONFIG_TINY_RCU. > It is also the reason this change doesn't need for stable. > > Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> > Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Applied for review and testing, thank you! Thanx, Paul > --- > kernel/rcu/rcu.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h > index a7ab2a023dd3..05f936ed167a 100644 > --- a/kernel/rcu/rcu.h > +++ b/kernel/rcu/rcu.h > @@ -254,7 +254,7 @@ void rcu_test_sync_prims(void); > */ > extern void resched_cpu(int cpu); > > -#if defined(SRCU) || !defined(TINY_RCU) > +#if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) > > #include <linux/rcu_node_tree.h> > > @@ -391,7 +391,7 @@ do { \ > #define raw_lockdep_assert_held_rcu_node(p) \ > lockdep_assert_held(&ACCESS_PRIVATE(p, lock)) > > -#endif /* #if defined(SRCU) || !defined(TINY_RCU) */ > +#endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */ > > #ifdef CONFIG_SRCU > void srcu_init(void); > -- > 2.20.1 > ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs 2019-10-15 10:23 [PATCH 0/7] rcu: cleanups Lai Jiangshan 2019-10-15 10:23 ` [PATCH 1/7] rcu: fix incorrect conditional compilation Lai Jiangshan @ 2019-10-15 10:23 ` Lai Jiangshan 2019-10-16 3:38 ` Paul E. McKenney 1 sibling, 1 reply; 7+ messages in thread From: Lai Jiangshan @ 2019-10-15 10:23 UTC (permalink / raw) To: linux-kernel Cc: Lai Jiangshan, Lai Jiangshan, Paul E. McKenney, Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Joel Fernandes, rcu "rcu_wait" is incorrct here, use "rcu_run" instead. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> --- kernel/rcu/tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 278798e58698..c351fc280945 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2485,7 +2485,7 @@ static void rcu_cpu_kthread(unsigned int cpu) int spincnt; for (spincnt = 0; spincnt < 10; spincnt++) { - trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait")); + trace_rcu_utilization(TPS("Start CPU kthread@rcu_run")); local_bh_disable(); *statusp = RCU_KTHREAD_RUNNING; local_irq_disable(); @@ -2496,7 +2496,7 @@ static void rcu_cpu_kthread(unsigned int cpu) rcu_core(); local_bh_enable(); if (*workp == 0) { - trace_rcu_utilization(TPS("End CPU kthread@rcu_wait")); + trace_rcu_utilization(TPS("End CPU kthread@rcu_run")); *statusp = RCU_KTHREAD_WAITING; return; } -- 2.20.1 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs 2019-10-15 10:23 ` [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs Lai Jiangshan @ 2019-10-16 3:38 ` Paul E. McKenney 2019-10-16 4:24 ` Lai Jiangshan 0 siblings, 1 reply; 7+ messages in thread From: Paul E. McKenney @ 2019-10-16 3:38 UTC (permalink / raw) To: Lai Jiangshan Cc: linux-kernel, Lai Jiangshan, Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Joel Fernandes, rcu On Tue, Oct 15, 2019 at 10:23:57AM +0000, Lai Jiangshan wrote: > "rcu_wait" is incorrct here, use "rcu_run" instead. > > Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> > Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> > --- > kernel/rcu/tree.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 278798e58698..c351fc280945 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -2485,7 +2485,7 @@ static void rcu_cpu_kthread(unsigned int cpu) > int spincnt; > > for (spincnt = 0; spincnt < 10; spincnt++) { > - trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait")); > + trace_rcu_utilization(TPS("Start CPU kthread@rcu_run")); > local_bh_disable(); > *statusp = RCU_KTHREAD_RUNNING; > local_irq_disable(); > @@ -2496,7 +2496,7 @@ static void rcu_cpu_kthread(unsigned int cpu) > rcu_core(); > local_bh_enable(); > if (*workp == 0) { > - trace_rcu_utilization(TPS("End CPU kthread@rcu_wait")); > + trace_rcu_utilization(TPS("End CPU kthread@rcu_run")); This one needs to stay as it was because this is where we wait when out of work. So I took the first hunk and dropped this second hunk. Please let me know if I am missing something. Thanx, Paul > *statusp = RCU_KTHREAD_WAITING; > return; > } > -- > 2.20.1 > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs 2019-10-16 3:38 ` Paul E. McKenney @ 2019-10-16 4:24 ` Lai Jiangshan 2019-10-16 14:14 ` Paul E. McKenney 0 siblings, 1 reply; 7+ messages in thread From: Lai Jiangshan @ 2019-10-16 4:24 UTC (permalink / raw) To: paulmck Cc: linux-kernel, Lai Jiangshan, Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Joel Fernandes, rcu On 2019/10/16 11:38 上午, Paul E. McKenney wrote: > On Tue, Oct 15, 2019 at 10:23:57AM +0000, Lai Jiangshan wrote: >> "rcu_wait" is incorrct here, use "rcu_run" instead. >> >> Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> >> Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> >> --- >> kernel/rcu/tree.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c >> index 278798e58698..c351fc280945 100644 >> --- a/kernel/rcu/tree.c >> +++ b/kernel/rcu/tree.c >> @@ -2485,7 +2485,7 @@ static void rcu_cpu_kthread(unsigned int cpu) >> int spincnt; >> >> for (spincnt = 0; spincnt < 10; spincnt++) { >> - trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait")); >> + trace_rcu_utilization(TPS("Start CPU kthread@rcu_run")); >> local_bh_disable(); >> *statusp = RCU_KTHREAD_RUNNING; >> local_irq_disable(); >> @@ -2496,7 +2496,7 @@ static void rcu_cpu_kthread(unsigned int cpu) >> rcu_core(); >> local_bh_enable(); >> if (*workp == 0) { >> - trace_rcu_utilization(TPS("End CPU kthread@rcu_wait")); >> + trace_rcu_utilization(TPS("End CPU kthread@rcu_run")); > > This one needs to stay as it was because this is where we wait when out > of work. I don't fully understand those TPS marks. If it is all about "where we wait when out of work", it ought to be "Start ... wait", rather than "End ... wait". The later one ("End ... wait") should be put before "for (spincnt = 0; spincnt < 10; spincnt++)" and remove the whole "rcu_run" as this patch suggested. To be honest, "rcu_run" is redundant since we already has TPS("Start RCU core"). Any ways, patch2&3 lose their relevance and should be dropped. Looking forward to your improved version. Thanks, Lai > > So I took the first hunk and dropped this second hunk. > > Please let me know if I am missing something. > > Thanx, Paul > >> *statusp = RCU_KTHREAD_WAITING; >> return; >> } >> -- >> 2.20.1 >> ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs 2019-10-16 4:24 ` Lai Jiangshan @ 2019-10-16 14:14 ` Paul E. McKenney 0 siblings, 0 replies; 7+ messages in thread From: Paul E. McKenney @ 2019-10-16 14:14 UTC (permalink / raw) To: Lai Jiangshan Cc: linux-kernel, Lai Jiangshan, Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Joel Fernandes, rcu On Wed, Oct 16, 2019 at 12:24:09PM +0800, Lai Jiangshan wrote: > > > On 2019/10/16 11:38 上午, Paul E. McKenney wrote: > > On Tue, Oct 15, 2019 at 10:23:57AM +0000, Lai Jiangshan wrote: > > > "rcu_wait" is incorrct here, use "rcu_run" instead. > > > > > > Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> > > > Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> > > > --- > > > kernel/rcu/tree.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > > index 278798e58698..c351fc280945 100644 > > > --- a/kernel/rcu/tree.c > > > +++ b/kernel/rcu/tree.c > > > @@ -2485,7 +2485,7 @@ static void rcu_cpu_kthread(unsigned int cpu) > > > int spincnt; > > > for (spincnt = 0; spincnt < 10; spincnt++) { > > > - trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait")); > > > + trace_rcu_utilization(TPS("Start CPU kthread@rcu_run")); > > > local_bh_disable(); > > > *statusp = RCU_KTHREAD_RUNNING; > > > local_irq_disable(); > > > @@ -2496,7 +2496,7 @@ static void rcu_cpu_kthread(unsigned int cpu) > > > rcu_core(); > > > local_bh_enable(); > > > if (*workp == 0) { > > > - trace_rcu_utilization(TPS("End CPU kthread@rcu_wait")); > > > + trace_rcu_utilization(TPS("End CPU kthread@rcu_run")); > > > > This one needs to stay as it was because this is where we wait when out > > of work. > > I don't fully understand those TPS marks. > > If it is all about "where we wait when out of work", it ought to > be "Start ... wait", rather than "End ... wait". The later one > ("End ... wait") should be put before > "for (spincnt = 0; spincnt < 10; spincnt++)" and remove > the whole "rcu_run" as this patch suggested. To be honest, > "rcu_run" is redundant since we already has TPS("Start RCU core"). > > Any ways, patch2&3 lose their relevance and should be dropped. > Looking forward to your improved version. Given that most of RCU's overhead is now in kthreads and in RCU_SOFTIRQ, perhaps trace_rcu_utilization() has outlived its usefulness, especially given the prospect of an RCU_SOFTIRQ-specific kthread. Thanx, Paul ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2019-10-16 14:14 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-10-15 10:23 [PATCH 0/7] rcu: cleanups Lai Jiangshan 2019-10-15 10:23 ` [PATCH 1/7] rcu: fix incorrect conditional compilation Lai Jiangshan 2019-10-16 3:35 ` Paul E. McKenney 2019-10-15 10:23 ` [PATCH 2/7] rcu: fix tracepoint string when RCU CPU kthread runs Lai Jiangshan 2019-10-16 3:38 ` Paul E. McKenney 2019-10-16 4:24 ` Lai Jiangshan 2019-10-16 14:14 ` Paul E. McKenney
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).