| Message ID | 20220520045645.1692124-1-qiang1.zhang@intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | rcu-tasks: Stop RCU Tasks scanning tasks which record on dyntick-idle entry | expand |
Hi Zqiang,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on paulmck-rcu/dev]
[also build test ERROR on v5.18-rc7 next-20220519]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Zqiang/rcu-tasks-Stop-RCU-Tasks-scanning-tasks-which-record-on-dyntick-idle-entry/20220520-125904
base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
config: m68k-defconfig (https://download.01.org/0day-ci/archive/20220520/202205201526.INo2g6TS-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/47ee19cf17eefb7dd696eabb583e5dcba4cd89e1
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Zqiang/rcu-tasks-Stop-RCU-Tasks-scanning-tasks-which-record-on-dyntick-idle-entry/20220520-125904
git checkout 47ee19cf17eefb7dd696eabb583e5dcba4cd89e1
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from kernel/rcu/update.c:606:
kernel/rcu/tasks.h: In function 'task_is_on_dyntick_idle':
>> kernel/rcu/tasks.h:212:34: error: 'struct task_struct' has no member named 'rcu_tasks_idle_cpu'
212 | t->rcu_tasks_idle_cpu >= 0;
| ^~
At top level:
kernel/rcu/tasks.h:209:13: warning: 'task_is_on_dyntick_idle' defined but not used [-Wunused-function]
209 | static bool task_is_on_dyntick_idle(struct task_struct *t)
| ^~~~~~~~~~~~~~~~~~~~~~~
vim +212 kernel/rcu/tasks.h
208
209 static bool task_is_on_dyntick_idle(struct task_struct *t)
210 {
211 return IS_ENABLED(CONFIG_NO_HZ_FULL) && !is_idle_task(t) &&
> 212 t->rcu_tasks_idle_cpu >= 0;
213 }
214
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index f6459343e4b6..7898da987581 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -206,6 +206,12 @@ static void set_tasks_gp_state(struct rcu_tasks *rtp, int newstate) rtp->gp_jiffies = jiffies; } +static bool task_is_on_dyntick_idle(struct task_struct *t) +{ + return IS_ENABLED(CONFIG_NO_HZ_FULL) && !is_idle_task(t) && + t->rcu_tasks_idle_cpu >= 0; +} + #ifndef CONFIG_TINY_RCU /* Return state name. */ static const char *tasks_gp_state_getname(struct rcu_tasks *rtp) @@ -812,7 +818,8 @@ static void rcu_tasks_pregp_step(struct list_head *hop) /* Per-task initial processing. */ static void rcu_tasks_pertask(struct task_struct *t, struct list_head *hop) { - if (t != current && READ_ONCE(t->on_rq) && !is_idle_task(t)) { + if (t != current && READ_ONCE(t->on_rq) && !is_idle_task(t) && + !task_is_on_dyntick_idle(t)) { get_task_struct(t); t->rcu_tasks_nvcsw = READ_ONCE(t->nvcsw); WRITE_ONCE(t->rcu_tasks_holdout, true); @@ -842,8 +849,7 @@ static void check_holdout_task(struct task_struct *t, if (!READ_ONCE(t->rcu_tasks_holdout) || t->rcu_tasks_nvcsw != READ_ONCE(t->nvcsw) || !READ_ONCE(t->on_rq) || - (IS_ENABLED(CONFIG_NO_HZ_FULL) && - !is_idle_task(t) && t->rcu_tasks_idle_cpu >= 0)) { + task_is_on_dyntick_idle(t)) { WRITE_ONCE(t->rcu_tasks_holdout, false); list_del_init(&t->rcu_tasks_holdout_list); put_task_struct(t);
When the RCU Tasks scanning on-rq tasks, there is no need to scanning tasks which record on dyntick-idle entry, at this time, these tasks are not remain within an RCU Tasks read-side critical section. This commit skip scanning tasks which record on dyntick-idle entry in rcu_tasks_pertask(). Signed-off-by: Zqiang <qiang1.zhang@intel.com> --- kernel/rcu/tasks.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)