Messages in this thread Patch in this message | | | Date | Wed, 23 Dec 2020 10:33:14 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [rcu:rcu/test 136/143] kernel/rcu/tree_plugin.h:2696:25: error: 'struct task_struct' has no member named 'on_cpu' |
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On Wed, Dec 23, 2020 at 11:28:58PM +0800, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/test > head: 4c4c8e04a7f8522de634aa062f4cd6b8b80c151b > commit: 72351a864d02b480a5c237144033e21be816f29f [136/143] fixup! rcu/nocb: Add grace period and task state to show_rcu_nocb_state() output > config: nds32-randconfig-r014-20201221 (attached as .config) > compiler: nds32le-linux-gcc (GCC) 9.3.0 > 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://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=72351a864d02b480a5c237144033e21be816f29f > git remote add rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > git fetch --no-tags rcu rcu/test > git checkout 72351a864d02b480a5c237144033e21be816f29f > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=nds32 > > 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 include/linux/kernel.h:16, > from kernel/rcu/tree.c:21: > kernel/rcu/tree_plugin.h: In function 'show_rcu_nocb_gp_state': > >> kernel/rcu/tree_plugin.h:2696:25: error: 'struct task_struct' has no member named 'on_cpu' > 2696 | !rdp->nocb_cb_kthread->on_cpu ? "!" : ""); > | ^~ > include/linux/printk.h:373:34: note: in definition of macro 'pr_info' > 373 | printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) > | ^~~~~~~~~~~ > kernel/rcu/tree_plugin.h: In function 'show_rcu_nocb_state': > kernel/rcu/tree_plugin.h:2737:25: error: 'struct task_struct' has no member named 'on_cpu' > 2737 | !rdp->nocb_cb_kthread->on_cpu ? "!" : ""); > | ^~ > include/linux/printk.h:373:34: note: in definition of macro 'pr_info' > 373 | printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) > | ^~~~~~~~~~~
Good catch, I missed the case of !SMP and rcu_nocbs CPUs, thank you!
Does the following fix this for you? (To be folded into the original with attribution.)
Thanx, Paul
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diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 2c16fa8..f97c991 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2668,6 +2668,19 @@ void rcu_bind_current_to_nocb(void) } EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb); +// The ->on_cpu field is available only in CONFIG_SMP=y, so... +#ifdef CONFIG_SMP +static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) +{ + return tsp && tsp->state == TASK_RUNNING && !tsp->on_cpu ? "!" : ""; +} +#else // #ifdef CONFIG_SMP +static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) +{ + return ""; +} +#endif // #else #ifdef CONFIG_SMP + /* * Dump out nocb grace-period kthread state for the specified rcu_data * structure. @@ -2693,8 +2706,7 @@ static void show_rcu_nocb_gp_state(struct rcu_data *rdp) rnp->grplo, rnp->grphi, READ_ONCE(rdp->nocb_gp_loops), rdp->nocb_gp_kthread ? task_state_to_char(rdp->nocb_gp_kthread) : '.', rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1, - rdp->nocb_cb_kthread && rdp->nocb_cb_kthread->state == TASK_RUNNING && - !rdp->nocb_cb_kthread->on_cpu ? "!" : ""); + show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread)); } /* Dump out nocb kthread state for the specified rcu_data structure. */ @@ -2734,8 +2746,7 @@ static void show_rcu_nocb_state(struct rcu_data *rdp) rcu_segcblist_n_cbs(&rdp->cblist), rdp->nocb_cb_kthread ? task_state_to_char(rdp->nocb_cb_kthread) : '.', rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1, - rdp->nocb_cb_kthread && rdp->nocb_cb_kthread->state == TASK_RUNNING && - !rdp->nocb_cb_kthread->on_cpu ? "!" : ""); + show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread)); /* It is OK for GP kthreads to have GP state. */ if (rdp->nocb_gp_rdp == rdp)
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