| Message ID | 20220816124839.1911-3-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | rcu/nocb: Delete local variable 'need_rcu_nocb_mask' in rcu_init_nohz() | expand |
Hi Zhen,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on paulmck-rcu/dev]
[also build test WARNING on linus/master v6.0-rc1 next-20220816]
[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#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131
base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
config: x86_64-randconfig-a004-20220815 (https://download.01.org/0day-ci/archive/20220817/202208170309.j1yYU9wN-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
# https://github.com/intel-lab-lkp/linux/commit/a1d5079765918764de3ff6e3e63fa2db7f7c14df
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131
git checkout a1d5079765918764de3ff6e3e63fa2db7f7c14df
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from kernel/rcu/tree.c:4801:
kernel/rcu/tree_nocb.h: In function 'rcu_init_nohz':
>> kernel/rcu/tree_nocb.h:1216:17: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
1216 | cpumask = cpu_possible_mask;
| ^
vim +/const +1216 kernel/rcu/tree_nocb.h
1208
1209 void __init rcu_init_nohz(void)
1210 {
1211 int cpu;
1212 struct rcu_data *rdp;
1213 struct cpumask *cpumask = NULL;
1214
1215 #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL)
> 1216 cpumask = cpu_possible_mask;
1217 #elif defined(CONFIG_NO_HZ_FULL)
1218 if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
1219 cpumask = tick_nohz_full_mask;
1220 #endif
1221
1222 if (cpumask) {
1223 if (!cpumask_available(rcu_nocb_mask)) {
1224 if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) {
1225 pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n");
1226 return;
1227 }
1228 }
1229
1230 cpumask_or(rcu_nocb_mask, rcu_nocb_mask, cpumask);
1231 }
1232
1233 if (!cpumask_available(rcu_nocb_mask))
1234 return;
1235
1236 if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) {
1237 pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n");
1238 cpumask_and(rcu_nocb_mask, cpu_possible_mask,
1239 rcu_nocb_mask);
1240 }
1241 if (cpumask_empty(rcu_nocb_mask))
1242 pr_info("\tOffload RCU callbacks from CPUs: (none).\n");
1243 else
1244 pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n",
1245 cpumask_pr_args(rcu_nocb_mask));
1246 if (rcu_nocb_poll)
1247 pr_info("\tPoll for callbacks from no-CBs CPUs.\n");
1248
1249 for_each_cpu(cpu, rcu_nocb_mask) {
1250 rdp = per_cpu_ptr(&rcu_data, cpu);
1251 if (rcu_segcblist_empty(&rdp->cblist))
1252 rcu_segcblist_init(&rdp->cblist);
1253 rcu_segcblist_offload(&rdp->cblist, true);
1254 rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP);
1255 rcu_segcblist_clear_flags(&rdp->cblist, SEGCBLIST_RCU_CORE);
1256 }
1257 rcu_organize_nocb_kthreads();
1258 }
1259
On 2022/8/17 3:55, kernel test robot wrote: > Hi Zhen, > > Thank you for the patch! Perhaps something to improve: > > [auto build test WARNING on paulmck-rcu/dev] > [also build test WARNING on linus/master v6.0-rc1 next-20220816] > [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#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131 > base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev > config: x86_64-randconfig-a004-20220815 (https://download.01.org/0day-ci/archive/20220817/202208170309.j1yYU9wN-lkp@intel.com/config) > compiler: gcc-11 (Debian 11.3.0-5) 11.3.0 > reproduce (this is a W=1 build): > # https://github.com/intel-lab-lkp/linux/commit/a1d5079765918764de3ff6e3e63fa2db7f7c14df > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131 > git checkout a1d5079765918764de3ff6e3e63fa2db7f7c14df > # save the config file > mkdir build_dir && cp config build_dir/.config > make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/ > > If you fix the issue, kindly add following tag where applicable > Reported-by: kernel test robot <lkp@intel.com> > > All warnings (new ones prefixed by >>): > > In file included from kernel/rcu/tree.c:4801: > kernel/rcu/tree_nocb.h: In function 'rcu_init_nohz': >>> kernel/rcu/tree_nocb.h:1216:17: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] > 1216 | cpumask = cpu_possible_mask; > | ^ > > > vim +/const +1216 kernel/rcu/tree_nocb.h It's a shame. Sorry, I forgot to check "> error.txt". > > 1208 > 1209 void __init rcu_init_nohz(void) > 1210 { > 1211 int cpu; > 1212 struct rcu_data *rdp; > 1213 struct cpumask *cpumask = NULL; > 1214 > 1215 #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL) >> 1216 cpumask = cpu_possible_mask; > 1217 #elif defined(CONFIG_NO_HZ_FULL) > 1218 if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask)) > 1219 cpumask = tick_nohz_full_mask; > 1220 #endif > 1221 > 1222 if (cpumask) { > 1223 if (!cpumask_available(rcu_nocb_mask)) { > 1224 if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) { > 1225 pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n"); > 1226 return; > 1227 } > 1228 } > 1229 > 1230 cpumask_or(rcu_nocb_mask, rcu_nocb_mask, cpumask); > 1231 } > 1232 > 1233 if (!cpumask_available(rcu_nocb_mask)) > 1234 return; > 1235 > 1236 if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { > 1237 pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n"); > 1238 cpumask_and(rcu_nocb_mask, cpu_possible_mask, > 1239 rcu_nocb_mask); > 1240 } > 1241 if (cpumask_empty(rcu_nocb_mask)) > 1242 pr_info("\tOffload RCU callbacks from CPUs: (none).\n"); > 1243 else > 1244 pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n", > 1245 cpumask_pr_args(rcu_nocb_mask)); > 1246 if (rcu_nocb_poll) > 1247 pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); > 1248 > 1249 for_each_cpu(cpu, rcu_nocb_mask) { > 1250 rdp = per_cpu_ptr(&rcu_data, cpu); > 1251 if (rcu_segcblist_empty(&rdp->cblist)) > 1252 rcu_segcblist_init(&rdp->cblist); > 1253 rcu_segcblist_offload(&rdp->cblist, true); > 1254 rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP); > 1255 rcu_segcblist_clear_flags(&rdp->cblist, SEGCBLIST_RCU_CORE); > 1256 } > 1257 rcu_organize_nocb_kthreads(); > 1258 } > 1259 >
Hi Zhen,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on paulmck-rcu/dev]
[also build test WARNING on linus/master v6.0-rc1 next-20220817]
[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#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131
base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
config: s390-randconfig-s052-20220818 (https://download.01.org/0day-ci/archive/20220818/202208180612.UVvfRJSR-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 12.1.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://github.com/intel-lab-lkp/linux/commit/a1d5079765918764de3ff6e3e63fa2db7f7c14df
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131
git checkout a1d5079765918764de3ff6e3e63fa2db7f7c14df
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=s390 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
sparse warnings: (new ones prefixed by >>)
kernel/rcu/tree.c: note: in included file:
>> kernel/rcu/tree_nocb.h:1216:17: sparse: sparse: incorrect type in assignment (different modifiers) @@ expected struct cpumask *cpumask @@ got struct cpumask const * @@
kernel/rcu/tree_nocb.h:1216:17: sparse: expected struct cpumask *cpumask
kernel/rcu/tree_nocb.h:1216:17: sparse: got struct cpumask const *
kernel/rcu/tree.c:1032:9: sparse: sparse: context imbalance in 'rcu_start_this_gp' - different lock contexts for basic block
kernel/rcu/tree.c:1413:9: sparse: sparse: context imbalance in 'rcu_poll_gp_seq_start_unlocked' - different lock contexts for basic block
kernel/rcu/tree.c:1428:9: sparse: sparse: context imbalance in 'rcu_poll_gp_seq_end_unlocked' - different lock contexts for basic block
kernel/rcu/tree.c:1544:9: sparse: sparse: context imbalance in 'rcu_gp_init' - different lock contexts for basic block
kernel/rcu/tree.c:2004:1: sparse: sparse: context imbalance in 'rcu_report_qs_rdp' - different lock contexts for basic block
kernel/rcu/tree.c:2186:13: sparse: sparse: context imbalance in 'rcu_do_batch' - wrong count at exit
kernel/rcu/tree.c:2371:9: sparse: sparse: context imbalance in 'force_qs_rnp' - different lock contexts for basic block
kernel/rcu/tree.c:2424:25: sparse: sparse: context imbalance in 'rcu_force_quiescent_state' - unexpected unlock
kernel/rcu/tree.c:2454:30: sparse: sparse: context imbalance in 'rcu_core' - different lock contexts for basic block
kernel/rcu/tree.c: note: in included file:
kernel/rcu/tree_exp.h:191:9: sparse: sparse: context imbalance in '__rcu_report_exp_rnp' - different lock contexts for basic block
kernel/rcu/tree_exp.h:1032:9: sparse: sparse: context imbalance in 'start_poll_synchronize_rcu_expedited' - different lock contexts for basic block
kernel/rcu/tree.c: note: in included file:
kernel/rcu/tree_nocb.h:134:16: sparse: sparse: context imbalance in 'rcu_nocb_bypass_trylock' - wrong count at exit
kernel/rcu/tree_nocb.h:151:13: sparse: sparse: context imbalance in 'rcu_nocb_lock' - wrong count at exit
kernel/rcu/tree_nocb.h:167:17: sparse: sparse: context imbalance in 'rcu_nocb_unlock' - unexpected unlock
kernel/rcu/tree_nocb.h:180:17: sparse: sparse: context imbalance in 'rcu_nocb_unlock_irqrestore' - unexpected unlock
kernel/rcu/tree_nocb.h:312:9: sparse: sparse: context imbalance in 'rcu_nocb_do_flush_bypass' - unexpected unlock
kernel/rcu/tree_nocb.h:327:13: sparse: sparse: context imbalance in 'rcu_nocb_flush_bypass' - wrong count at exit
kernel/rcu/tree_nocb.h:489:13: sparse: sparse: context imbalance in '__call_rcu_nocb_wake' - wrong count at exit
kernel/rcu/tree_nocb.h:581:9: sparse: sparse: context imbalance in 'nocb_gp_toggle_rdp' - wrong count at exit
kernel/rcu/tree_nocb.h:635:9: sparse: sparse: context imbalance in 'nocb_gp_wait' - different lock contexts for basic block
kernel/rcu/tree_nocb.h:888:9: sparse: sparse: context imbalance in 'nocb_cb_wait' - wrong count at exit
kernel/rcu/tree_nocb.h:1002:9: sparse: sparse: context imbalance in 'rdp_offload_toggle' - wrong count at exit
kernel/rcu/tree_nocb.h:1086:34: sparse: sparse: context imbalance in 'rcu_nocb_rdp_deoffload' - different lock contexts for basic block
kernel/rcu/tree_nocb.h:1124:13: sparse: sparse: context imbalance in 'rcu_nocb_rdp_offload' - different lock contexts for basic block
vim +1216 kernel/rcu/tree_nocb.h
1208
1209 void __init rcu_init_nohz(void)
1210 {
1211 int cpu;
1212 struct rcu_data *rdp;
1213 struct cpumask *cpumask = NULL;
1214
1215 #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL)
> 1216 cpumask = cpu_possible_mask;
1217 #elif defined(CONFIG_NO_HZ_FULL)
1218 if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
1219 cpumask = tick_nohz_full_mask;
1220 #endif
1221
1222 if (cpumask) {
1223 if (!cpumask_available(rcu_nocb_mask)) {
1224 if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) {
1225 pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n");
1226 return;
1227 }
1228 }
1229
1230 cpumask_or(rcu_nocb_mask, rcu_nocb_mask, cpumask);
1231 }
1232
1233 if (!cpumask_available(rcu_nocb_mask))
1234 return;
1235
1236 if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) {
1237 pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n");
1238 cpumask_and(rcu_nocb_mask, cpu_possible_mask,
1239 rcu_nocb_mask);
1240 }
1241 if (cpumask_empty(rcu_nocb_mask))
1242 pr_info("\tOffload RCU callbacks from CPUs: (none).\n");
1243 else
1244 pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n",
1245 cpumask_pr_args(rcu_nocb_mask));
1246 if (rcu_nocb_poll)
1247 pr_info("\tPoll for callbacks from no-CBs CPUs.\n");
1248
1249 for_each_cpu(cpu, rcu_nocb_mask) {
1250 rdp = per_cpu_ptr(&rcu_data, cpu);
1251 if (rcu_segcblist_empty(&rdp->cblist))
1252 rcu_segcblist_init(&rdp->cblist);
1253 rcu_segcblist_offload(&rdp->cblist, true);
1254 rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP);
1255 rcu_segcblist_clear_flags(&rdp->cblist, SEGCBLIST_RCU_CORE);
1256 }
1257 rcu_organize_nocb_kthreads();
1258 }
1259
Hi Zhen,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on paulmck-rcu/dev]
[also build test ERROR on linus/master v6.0-rc1 next-20220817]
[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#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131
base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
config: hexagon-randconfig-r041-20220818 (https://download.01.org/0day-ci/archive/20220818/202208180940.Jks0rOXz-lkp@intel.com/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project aed5e3bea138ce581d682158eb61c27b3cfdd6ec)
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/a1d5079765918764de3ff6e3e63fa2db7f7c14df
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131
git checkout a1d5079765918764de3ff6e3e63fa2db7f7c14df
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from kernel/rcu/tree.c:4801:
>> kernel/rcu/tree_nocb.h:1216:10: error: assigning to 'struct cpumask *' from 'const struct cpumask *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
cpumask = cpu_possible_mask;
^ ~~~~~~~~~~~~~~~~~
1 error generated.
vim +1216 kernel/rcu/tree_nocb.h
1208
1209 void __init rcu_init_nohz(void)
1210 {
1211 int cpu;
1212 struct rcu_data *rdp;
1213 struct cpumask *cpumask = NULL;
1214
1215 #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL)
> 1216 cpumask = cpu_possible_mask;
1217 #elif defined(CONFIG_NO_HZ_FULL)
1218 if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
1219 cpumask = tick_nohz_full_mask;
1220 #endif
1221
1222 if (cpumask) {
1223 if (!cpumask_available(rcu_nocb_mask)) {
1224 if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) {
1225 pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n");
1226 return;
1227 }
1228 }
1229
1230 cpumask_or(rcu_nocb_mask, rcu_nocb_mask, cpumask);
1231 }
1232
1233 if (!cpumask_available(rcu_nocb_mask))
1234 return;
1235
1236 if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) {
1237 pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n");
1238 cpumask_and(rcu_nocb_mask, cpu_possible_mask,
1239 rcu_nocb_mask);
1240 }
1241 if (cpumask_empty(rcu_nocb_mask))
1242 pr_info("\tOffload RCU callbacks from CPUs: (none).\n");
1243 else
1244 pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n",
1245 cpumask_pr_args(rcu_nocb_mask));
1246 if (rcu_nocb_poll)
1247 pr_info("\tPoll for callbacks from no-CBs CPUs.\n");
1248
1249 for_each_cpu(cpu, rcu_nocb_mask) {
1250 rdp = per_cpu_ptr(&rcu_data, cpu);
1251 if (rcu_segcblist_empty(&rdp->cblist))
1252 rcu_segcblist_init(&rdp->cblist);
1253 rcu_segcblist_offload(&rdp->cblist, true);
1254 rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP);
1255 rcu_segcblist_clear_flags(&rdp->cblist, SEGCBLIST_RCU_CORE);
1256 }
1257 rcu_organize_nocb_kthreads();
1258 }
1259
On 2022/8/18 9:19, kernel test robot wrote: > Hi Zhen, > > Thank you for the patch! Yet something to improve: > > [auto build test ERROR on paulmck-rcu/dev] > [also build test ERROR on linus/master v6.0-rc1 next-20220817] > [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#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131 > base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev > config: hexagon-randconfig-r041-20220818 (https://download.01.org/0day-ci/archive/20220818/202208180940.Jks0rOXz-lkp@intel.com/config) > compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project aed5e3bea138ce581d682158eb61c27b3cfdd6ec) > 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/a1d5079765918764de3ff6e3e63fa2db7f7c14df > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131 > git checkout a1d5079765918764de3ff6e3e63fa2db7f7c14df > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/ > > If you fix the issue, kindly add following tag where applicable > Reported-by: kernel test robot <lkp@intel.com> > > All errors (new ones prefixed by >>): > > In file included from kernel/rcu/tree.c:4801: >>> kernel/rcu/tree_nocb.h:1216:10: error: assigning to 'struct cpumask *' from 'const struct cpumask *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers] > cpumask = cpu_possible_mask; > ^ ~~~~~~~~~~~~~~~~~ > 1 error generated. I fixed it yesterday and post v4. Please check for v4. > > > vim +1216 kernel/rcu/tree_nocb.h > > 1208 > 1209 void __init rcu_init_nohz(void) > 1210 { > 1211 int cpu; > 1212 struct rcu_data *rdp; > 1213 struct cpumask *cpumask = NULL; > 1214 > 1215 #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL) >> 1216 cpumask = cpu_possible_mask; > 1217 #elif defined(CONFIG_NO_HZ_FULL) > 1218 if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask)) > 1219 cpumask = tick_nohz_full_mask; > 1220 #endif > 1221 > 1222 if (cpumask) { > 1223 if (!cpumask_available(rcu_nocb_mask)) { > 1224 if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) { > 1225 pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n"); > 1226 return; > 1227 } > 1228 } > 1229 > 1230 cpumask_or(rcu_nocb_mask, rcu_nocb_mask, cpumask); > 1231 } > 1232 > 1233 if (!cpumask_available(rcu_nocb_mask)) > 1234 return; > 1235 > 1236 if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { > 1237 pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n"); > 1238 cpumask_and(rcu_nocb_mask, cpu_possible_mask, > 1239 rcu_nocb_mask); > 1240 } > 1241 if (cpumask_empty(rcu_nocb_mask)) > 1242 pr_info("\tOffload RCU callbacks from CPUs: (none).\n"); > 1243 else > 1244 pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n", > 1245 cpumask_pr_args(rcu_nocb_mask)); > 1246 if (rcu_nocb_poll) > 1247 pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); > 1248 > 1249 for_each_cpu(cpu, rcu_nocb_mask) { > 1250 rdp = per_cpu_ptr(&rcu_data, cpu); > 1251 if (rcu_segcblist_empty(&rdp->cblist)) > 1252 rcu_segcblist_init(&rdp->cblist); > 1253 rcu_segcblist_offload(&rdp->cblist, true); > 1254 rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP); > 1255 rcu_segcblist_clear_flags(&rdp->cblist, SEGCBLIST_RCU_CORE); > 1256 } > 1257 rcu_organize_nocb_kthreads(); > 1258 } > 1259 >
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h index ff763e7dc53551f..07b415e8117a10a 100644 --- a/kernel/rcu/tree_nocb.h +++ b/kernel/rcu/tree_nocb.h @@ -1209,44 +1209,30 @@ EXPORT_SYMBOL_GPL(rcu_nocb_cpu_offload); void __init rcu_init_nohz(void) { int cpu; - bool need_rcu_nocb_mask = false; - bool offload_all = false; struct rcu_data *rdp; + struct cpumask *cpumask = NULL; #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL) - if (!cpumask_available(rcu_nocb_mask)) { - need_rcu_nocb_mask = true; - offload_all = true; - } -#endif /* #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL) */ - -#if defined(CONFIG_NO_HZ_FULL) - if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask)) { - need_rcu_nocb_mask = true; - offload_all = false; /* NO_HZ_FULL has its own mask. */ - } -#endif /* #if defined(CONFIG_NO_HZ_FULL) */ + cpumask = cpu_possible_mask; +#elif defined(CONFIG_NO_HZ_FULL) + if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask)) + cpumask = tick_nohz_full_mask; +#endif - if (need_rcu_nocb_mask) { + if (cpumask) { if (!cpumask_available(rcu_nocb_mask)) { if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) { pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n"); return; } } + + cpumask_or(rcu_nocb_mask, rcu_nocb_mask, cpumask); } if (!cpumask_available(rcu_nocb_mask)) return; -#if defined(CONFIG_NO_HZ_FULL) - if (tick_nohz_full_running) - cpumask_or(rcu_nocb_mask, rcu_nocb_mask, tick_nohz_full_mask); -#endif /* #if defined(CONFIG_NO_HZ_FULL) */ - - if (offload_all) - cpumask_setall(rcu_nocb_mask); - if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n"); cpumask_and(rcu_nocb_mask, cpu_possible_mask,
When CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y or CONFIG_NO_HZ_FULL=y, additional CPUs need to be added to 'rcu_nocb_mask'. But 'rcu_nocb_mask' may be not available now, due to 'rcu_nocbs' is not specified. Check and initialize 'rcu_nocb_mask' before using it. This code simplification strictly follows this logic, compared with old implementations, unnecessary crossovers are avoided and easy to understand. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- kernel/rcu/tree_nocb.h | 32 +++++++++----------------------- 1 file changed, 9 insertions(+), 23 deletions(-)