* [rcu:rcu/next 110/168] kernel/rcu/tree.c:3401:2: error: implicit declaration of function 'ASSERT_EXCLUSIVE_WRITER'
@ 2020-02-22 7:27 kbuild test robot
2020-02-22 16:33 ` Paul E. McKenney
0 siblings, 1 reply; 2+ messages in thread
From: kbuild test robot @ 2020-02-22 7:27 UTC (permalink / raw)
To: Paul E. McKenney; +Cc: kbuild-all, linux-kernel
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tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/next
head: 8aa63de65a79bd8c5c1c2b19452e35f58b043ac7
commit: e70e4b3e69ce8d3fdfc1f4bfe6ed27187e1a9016 [110/168] rcu: Mark rcu_state.ncpus to detect concurrent writes
config: arc-defconfig (attached as .config)
compiler: arc-elf-gcc (GCC) 9.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout e70e4b3e69ce8d3fdfc1f4bfe6ed27187e1a9016
# save the attached .config to linux build tree
GCC_VERSION=9.2.0 make.cross ARCH=arc
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>
Note: the rcu/rcu/next HEAD 8aa63de65a79bd8c5c1c2b19452e35f58b043ac7 builds fine.
It only hurts bisectibility.
All errors (new ones prefixed by >>):
kernel/rcu/tree.c: In function 'rcu_cpu_starting':
>> kernel/rcu/tree.c:3401:2: error: implicit declaration of function 'ASSERT_EXCLUSIVE_WRITER' [-Werror=implicit-function-declaration]
3401 | ASSERT_EXCLUSIVE_WRITER(rcu_state.ncpus);
| ^~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
vim +/ASSERT_EXCLUSIVE_WRITER +3401 kernel/rcu/tree.c
3364
3365 /*
3366 * Mark the specified CPU as being online so that subsequent grace periods
3367 * (both expedited and normal) will wait on it. Note that this means that
3368 * incoming CPUs are not allowed to use RCU read-side critical sections
3369 * until this function is called. Failing to observe this restriction
3370 * will result in lockdep splats.
3371 *
3372 * Note that this function is special in that it is invoked directly
3373 * from the incoming CPU rather than from the cpuhp_step mechanism.
3374 * This is because this function must be invoked at a precise location.
3375 */
3376 void rcu_cpu_starting(unsigned int cpu)
3377 {
3378 unsigned long flags;
3379 unsigned long mask;
3380 int nbits;
3381 unsigned long oldmask;
3382 struct rcu_data *rdp;
3383 struct rcu_node *rnp;
3384
3385 if (per_cpu(rcu_cpu_started, cpu))
3386 return;
3387
3388 per_cpu(rcu_cpu_started, cpu) = 1;
3389
3390 rdp = per_cpu_ptr(&rcu_data, cpu);
3391 rnp = rdp->mynode;
3392 mask = rdp->grpmask;
3393 raw_spin_lock_irqsave_rcu_node(rnp, flags);
3394 WRITE_ONCE(rnp->qsmaskinitnext, rnp->qsmaskinitnext | mask);
3395 oldmask = rnp->expmaskinitnext;
3396 rnp->expmaskinitnext |= mask;
3397 oldmask ^= rnp->expmaskinitnext;
3398 nbits = bitmap_weight(&oldmask, BITS_PER_LONG);
3399 /* Allow lockless access for expedited grace periods. */
3400 smp_store_release(&rcu_state.ncpus, rcu_state.ncpus + nbits); /* ^^^ */
> 3401 ASSERT_EXCLUSIVE_WRITER(rcu_state.ncpus);
3402 rcu_gpnum_ovf(rnp, rdp); /* Offline-induced counter wrap? */
3403 rdp->rcu_onl_gp_seq = READ_ONCE(rcu_state.gp_seq);
3404 rdp->rcu_onl_gp_flags = READ_ONCE(rcu_state.gp_flags);
3405 if (rnp->qsmask & mask) { /* RCU waiting on incoming CPU? */
3406 rcu_disable_urgency_upon_qs(rdp);
3407 /* Report QS -after- changing ->qsmaskinitnext! */
3408 rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
3409 } else {
3410 raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
3411 }
3412 smp_mb(); /* Ensure RCU read-side usage follows above initialization. */
3413 }
3414
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [rcu:rcu/next 110/168] kernel/rcu/tree.c:3401:2: error: implicit declaration of function 'ASSERT_EXCLUSIVE_WRITER'
2020-02-22 7:27 [rcu:rcu/next 110/168] kernel/rcu/tree.c:3401:2: error: implicit declaration of function 'ASSERT_EXCLUSIVE_WRITER' kbuild test robot
@ 2020-02-22 16:33 ` Paul E. McKenney
0 siblings, 0 replies; 2+ messages in thread
From: Paul E. McKenney @ 2020-02-22 16:33 UTC (permalink / raw)
To: kbuild test robot; +Cc: kbuild-all, linux-kernel
On Sat, Feb 22, 2020 at 03:27:04PM +0800, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/next
> head: 8aa63de65a79bd8c5c1c2b19452e35f58b043ac7
> commit: e70e4b3e69ce8d3fdfc1f4bfe6ed27187e1a9016 [110/168] rcu: Mark rcu_state.ncpus to detect concurrent writes
> config: arc-defconfig (attached as .config)
> compiler: arc-elf-gcc (GCC) 9.2.0
> reproduce:
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> git checkout e70e4b3e69ce8d3fdfc1f4bfe6ed27187e1a9016
> # save the attached .config to linux build tree
> GCC_VERSION=9.2.0 make.cross ARCH=arc
>
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
>
> Note: the rcu/rcu/next HEAD 8aa63de65a79bd8c5c1c2b19452e35f58b043ac7 builds fine.
> It only hurts bisectibility.
>
> All errors (new ones prefixed by >>):
>
> kernel/rcu/tree.c: In function 'rcu_cpu_starting':
> >> kernel/rcu/tree.c:3401:2: error: implicit declaration of function 'ASSERT_EXCLUSIVE_WRITER' [-Werror=implicit-function-declaration]
> 3401 | ASSERT_EXCLUSIVE_WRITER(rcu_state.ncpus);
> | ^~~~~~~~~~~~~~~~~~~~~~~
> cc1: some warnings being treated as errors
Good catch! I will move this out of the set of commits intended for
v5.7, thank you!
Thanx, Paul
> vim +/ASSERT_EXCLUSIVE_WRITER +3401 kernel/rcu/tree.c
>
> 3364
> 3365 /*
> 3366 * Mark the specified CPU as being online so that subsequent grace periods
> 3367 * (both expedited and normal) will wait on it. Note that this means that
> 3368 * incoming CPUs are not allowed to use RCU read-side critical sections
> 3369 * until this function is called. Failing to observe this restriction
> 3370 * will result in lockdep splats.
> 3371 *
> 3372 * Note that this function is special in that it is invoked directly
> 3373 * from the incoming CPU rather than from the cpuhp_step mechanism.
> 3374 * This is because this function must be invoked at a precise location.
> 3375 */
> 3376 void rcu_cpu_starting(unsigned int cpu)
> 3377 {
> 3378 unsigned long flags;
> 3379 unsigned long mask;
> 3380 int nbits;
> 3381 unsigned long oldmask;
> 3382 struct rcu_data *rdp;
> 3383 struct rcu_node *rnp;
> 3384
> 3385 if (per_cpu(rcu_cpu_started, cpu))
> 3386 return;
> 3387
> 3388 per_cpu(rcu_cpu_started, cpu) = 1;
> 3389
> 3390 rdp = per_cpu_ptr(&rcu_data, cpu);
> 3391 rnp = rdp->mynode;
> 3392 mask = rdp->grpmask;
> 3393 raw_spin_lock_irqsave_rcu_node(rnp, flags);
> 3394 WRITE_ONCE(rnp->qsmaskinitnext, rnp->qsmaskinitnext | mask);
> 3395 oldmask = rnp->expmaskinitnext;
> 3396 rnp->expmaskinitnext |= mask;
> 3397 oldmask ^= rnp->expmaskinitnext;
> 3398 nbits = bitmap_weight(&oldmask, BITS_PER_LONG);
> 3399 /* Allow lockless access for expedited grace periods. */
> 3400 smp_store_release(&rcu_state.ncpus, rcu_state.ncpus + nbits); /* ^^^ */
> > 3401 ASSERT_EXCLUSIVE_WRITER(rcu_state.ncpus);
> 3402 rcu_gpnum_ovf(rnp, rdp); /* Offline-induced counter wrap? */
> 3403 rdp->rcu_onl_gp_seq = READ_ONCE(rcu_state.gp_seq);
> 3404 rdp->rcu_onl_gp_flags = READ_ONCE(rcu_state.gp_flags);
> 3405 if (rnp->qsmask & mask) { /* RCU waiting on incoming CPU? */
> 3406 rcu_disable_urgency_upon_qs(rdp);
> 3407 /* Report QS -after- changing ->qsmaskinitnext! */
> 3408 rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
> 3409 } else {
> 3410 raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
> 3411 }
> 3412 smp_mb(); /* Ensure RCU read-side usage follows above initialization. */
> 3413 }
> 3414
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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2020-02-22 7:27 [rcu:rcu/next 110/168] kernel/rcu/tree.c:3401:2: error: implicit declaration of function 'ASSERT_EXCLUSIVE_WRITER' kbuild test robot
2020-02-22 16:33 ` Paul E. McKenney
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