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* [ammarfaizi2-block:paulmck/linux-rcu/dev 80/85] kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used
@ 2022-01-25 11:24 kernel test robot
  2022-01-25 19:01 ` Paul E. McKenney
  0 siblings, 1 reply; 3+ messages in thread
From: kernel test robot @ 2022-01-25 11:24 UTC (permalink / raw)
  To: Paul E. McKenney; +Cc: kbuild-all, GNU/Weeb Mailing List, linux-kernel

tree:   https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/dev
head:   3cd375aa70d563fe8aa3e5f03280bdd8a334de45
commit: 2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62 [80/85] squash! srcu: Make Tree SRCU able to operate without snp_node array
config: nds32-defconfig (https://download.01.org/0day-ci/archive/20220125/202201251933.iaAyduWp-lkp@intel.com/config)
compiler: nds32le-linux-gcc (GCC) 11.2.0
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/ammarfaizi2/linux-block/commit/2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/dev
        git checkout 2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=nds32 SHELL=/bin/bash kernel/rcu/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   kernel/rcu/srcutree.c: In function 'srcu_barrier':
>> kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used [-Wunused-but-set-variable]
    1168 |         struct srcu_data *sdp;
         |                           ^~~


vim +/sdp +1168 kernel/rcu/srcutree.c

2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1160  
dad81a2026841b Paul E. McKenney 2017-03-25  1161  /**
dad81a2026841b Paul E. McKenney 2017-03-25  1162   * srcu_barrier - Wait until all in-flight call_srcu() callbacks complete.
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1163   * @ssp: srcu_struct on which to wait for in-flight callbacks.
dad81a2026841b Paul E. McKenney 2017-03-25  1164   */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1165  void srcu_barrier(struct srcu_struct *ssp)
dad81a2026841b Paul E. McKenney 2017-03-25  1166  {
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1167  	int cpu;
da915ad5cf25b5 Paul E. McKenney 2017-04-05 @1168  	struct srcu_data *sdp;
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1169  	unsigned long s = rcu_seq_snap(&ssp->srcu_barrier_seq);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1170  
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1171  	check_init_srcu_struct(ssp);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1172  	mutex_lock(&ssp->srcu_barrier_mutex);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1173  	if (rcu_seq_done(&ssp->srcu_barrier_seq, s)) {
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1174  		smp_mb(); /* Force ordering following return. */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1175  		mutex_unlock(&ssp->srcu_barrier_mutex);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1176  		return; /* Someone else did our work for us. */
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1177  	}
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1178  	rcu_seq_start(&ssp->srcu_barrier_seq);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1179  	init_completion(&ssp->srcu_barrier_completion);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1180  
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1181  	/* Initial count prevents reaching zero until all CBs are posted. */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1182  	atomic_set(&ssp->srcu_barrier_cpu_cnt, 1);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1183  
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1184  	if (!smp_load_acquire(&ssp->srcu_size_state)) {
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1185  		srcu_barrier_one_cpu(ssp, per_cpu_ptr(ssp->sda, 0));
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1186  	} else {
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1187  
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1188  		/*
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1189  		 * Each pass through this loop enqueues a callback, but only
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1190  		 * on CPUs already having callbacks enqueued.  Note that if
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1191  		 * a CPU already has callbacks enqueue, it must have already
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1192  		 * registered the need for a future grace period, so all we
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1193  		 * need do is enqueue a callback that will use the same
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1194  		 * grace period as the last callback already in the queue.
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1195  		 */
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1196  		for_each_possible_cpu(cpu) {
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1197  			sdp = per_cpu_ptr(ssp->sda, cpu);
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1198  			srcu_barrier_one_cpu(ssp, per_cpu_ptr(ssp->sda, cpu));
a602538e46c9c6 Paul E. McKenney 2017-04-28  1199  		}
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1200  	}
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1201  
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1202  	/* Remove the initial count, at which point reaching zero can happen. */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1203  	if (atomic_dec_and_test(&ssp->srcu_barrier_cpu_cnt))
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1204  		complete(&ssp->srcu_barrier_completion);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1205  	wait_for_completion(&ssp->srcu_barrier_completion);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1206  
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1207  	rcu_seq_end(&ssp->srcu_barrier_seq);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1208  	mutex_unlock(&ssp->srcu_barrier_mutex);
dad81a2026841b Paul E. McKenney 2017-03-25  1209  }
dad81a2026841b Paul E. McKenney 2017-03-25  1210  EXPORT_SYMBOL_GPL(srcu_barrier);
dad81a2026841b Paul E. McKenney 2017-03-25  1211  

:::::: The code at line 1168 was first introduced by commit
:::::: da915ad5cf25b5f5d358dd3670c3378d8ae8c03e srcu: Parallelize callback handling

:::::: TO: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
:::::: CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [ammarfaizi2-block:paulmck/linux-rcu/dev 80/85] kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used
  2022-01-25 11:24 [ammarfaizi2-block:paulmck/linux-rcu/dev 80/85] kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used kernel test robot
@ 2022-01-25 19:01 ` Paul E. McKenney
  0 siblings, 0 replies; 3+ messages in thread
From: Paul E. McKenney @ 2022-01-25 19:01 UTC (permalink / raw)
  To: kernel test robot; +Cc: kbuild-all, GNU/Weeb Mailing List, linux-kernel

On Tue, Jan 25, 2022 at 07:24:14PM +0800, kernel test robot wrote:
> tree:   https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/dev
> head:   3cd375aa70d563fe8aa3e5f03280bdd8a334de45
> commit: 2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62 [80/85] squash! srcu: Make Tree SRCU able to operate without snp_node array
> config: nds32-defconfig (https://download.01.org/0day-ci/archive/20220125/202201251933.iaAyduWp-lkp@intel.com/config)
> compiler: nds32le-linux-gcc (GCC) 11.2.0
> 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/ammarfaizi2/linux-block/commit/2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62
>         git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
>         git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/dev
>         git checkout 2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62
>         # save the config file to linux build tree
>         mkdir build_dir
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=nds32 SHELL=/bin/bash kernel/rcu/
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
>    kernel/rcu/srcutree.c: In function 'srcu_barrier':
> >> kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used [-Wunused-but-set-variable]
>     1168 |         struct srcu_data *sdp;
>          |                           ^~~

Fixed in e3ec4a4e8733 ("srcu: Make Tree SRCU able to operate without
snp_node array").

Thank you for your testing efforts!

							Thanx, Paul

> vim +/sdp +1168 kernel/rcu/srcutree.c
> 
> 2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1160  
> dad81a2026841b Paul E. McKenney 2017-03-25  1161  /**
> dad81a2026841b Paul E. McKenney 2017-03-25  1162   * srcu_barrier - Wait until all in-flight call_srcu() callbacks complete.
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1163   * @ssp: srcu_struct on which to wait for in-flight callbacks.
> dad81a2026841b Paul E. McKenney 2017-03-25  1164   */
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1165  void srcu_barrier(struct srcu_struct *ssp)
> dad81a2026841b Paul E. McKenney 2017-03-25  1166  {
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1167  	int cpu;
> da915ad5cf25b5 Paul E. McKenney 2017-04-05 @1168  	struct srcu_data *sdp;
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1169  	unsigned long s = rcu_seq_snap(&ssp->srcu_barrier_seq);
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1170  
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1171  	check_init_srcu_struct(ssp);
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1172  	mutex_lock(&ssp->srcu_barrier_mutex);
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1173  	if (rcu_seq_done(&ssp->srcu_barrier_seq, s)) {
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1174  		smp_mb(); /* Force ordering following return. */
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1175  		mutex_unlock(&ssp->srcu_barrier_mutex);
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1176  		return; /* Someone else did our work for us. */
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1177  	}
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1178  	rcu_seq_start(&ssp->srcu_barrier_seq);
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1179  	init_completion(&ssp->srcu_barrier_completion);
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1180  
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1181  	/* Initial count prevents reaching zero until all CBs are posted. */
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1182  	atomic_set(&ssp->srcu_barrier_cpu_cnt, 1);
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1183  
> 2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1184  	if (!smp_load_acquire(&ssp->srcu_size_state)) {
> 2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1185  		srcu_barrier_one_cpu(ssp, per_cpu_ptr(ssp->sda, 0));
> 2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1186  	} else {
> 2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1187  
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1188  		/*
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1189  		 * Each pass through this loop enqueues a callback, but only
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1190  		 * on CPUs already having callbacks enqueued.  Note that if
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1191  		 * a CPU already has callbacks enqueue, it must have already
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1192  		 * registered the need for a future grace period, so all we
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1193  		 * need do is enqueue a callback that will use the same
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1194  		 * grace period as the last callback already in the queue.
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1195  		 */
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1196  		for_each_possible_cpu(cpu) {
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1197  			sdp = per_cpu_ptr(ssp->sda, cpu);
> 2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1198  			srcu_barrier_one_cpu(ssp, per_cpu_ptr(ssp->sda, cpu));
> a602538e46c9c6 Paul E. McKenney 2017-04-28  1199  		}
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1200  	}
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1201  
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1202  	/* Remove the initial count, at which point reaching zero can happen. */
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1203  	if (atomic_dec_and_test(&ssp->srcu_barrier_cpu_cnt))
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1204  		complete(&ssp->srcu_barrier_completion);
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1205  	wait_for_completion(&ssp->srcu_barrier_completion);
> da915ad5cf25b5 Paul E. McKenney 2017-04-05  1206  
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1207  	rcu_seq_end(&ssp->srcu_barrier_seq);
> aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1208  	mutex_unlock(&ssp->srcu_barrier_mutex);
> dad81a2026841b Paul E. McKenney 2017-03-25  1209  }
> dad81a2026841b Paul E. McKenney 2017-03-25  1210  EXPORT_SYMBOL_GPL(srcu_barrier);
> dad81a2026841b Paul E. McKenney 2017-03-25  1211  
> 
> :::::: The code at line 1168 was first introduced by commit
> :::::: da915ad5cf25b5f5d358dd3670c3378d8ae8c03e srcu: Parallelize callback handling
> 
> :::::: TO: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> :::::: CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

^ permalink raw reply	[flat|nested] 3+ messages in thread
* [ammarfaizi2-block:paulmck/linux-rcu/dev 80/85] kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used
@ 2022-01-25 11:34 kernel test robot
  0 siblings, 0 replies; 3+ messages in thread
From: kernel test robot @ 2022-01-25 11:34 UTC (permalink / raw)
  To: Paul E. McKenney; +Cc: kbuild-all, GNU/Weeb Mailing List, linux-kernel

tree:   https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/dev
head:   3cd375aa70d563fe8aa3e5f03280bdd8a334de45
commit: 2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62 [80/85] squash! srcu: Make Tree SRCU able to operate without snp_node array
config: arc-randconfig-r043-20220124 (https://download.01.org/0day-ci/archive/20220125/202201251951.fCJTBQJd-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 11.2.0
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/ammarfaizi2/linux-block/commit/2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/dev
        git checkout 2c773bcaf4dd5031d0b2c980cc623ecfbcc6ab62
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arc SHELL=/bin/bash kernel/rcu/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   kernel/rcu/srcutree.c: In function 'srcu_barrier':
>> kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used [-Wunused-but-set-variable]
    1168 |         struct srcu_data *sdp;
         |                           ^~~


vim +/sdp +1168 kernel/rcu/srcutree.c

2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1160  
dad81a2026841b Paul E. McKenney 2017-03-25  1161  /**
dad81a2026841b Paul E. McKenney 2017-03-25  1162   * srcu_barrier - Wait until all in-flight call_srcu() callbacks complete.
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1163   * @ssp: srcu_struct on which to wait for in-flight callbacks.
dad81a2026841b Paul E. McKenney 2017-03-25  1164   */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1165  void srcu_barrier(struct srcu_struct *ssp)
dad81a2026841b Paul E. McKenney 2017-03-25  1166  {
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1167  	int cpu;
da915ad5cf25b5 Paul E. McKenney 2017-04-05 @1168  	struct srcu_data *sdp;
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1169  	unsigned long s = rcu_seq_snap(&ssp->srcu_barrier_seq);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1170  
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1171  	check_init_srcu_struct(ssp);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1172  	mutex_lock(&ssp->srcu_barrier_mutex);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1173  	if (rcu_seq_done(&ssp->srcu_barrier_seq, s)) {
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1174  		smp_mb(); /* Force ordering following return. */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1175  		mutex_unlock(&ssp->srcu_barrier_mutex);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1176  		return; /* Someone else did our work for us. */
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1177  	}
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1178  	rcu_seq_start(&ssp->srcu_barrier_seq);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1179  	init_completion(&ssp->srcu_barrier_completion);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1180  
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1181  	/* Initial count prevents reaching zero until all CBs are posted. */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1182  	atomic_set(&ssp->srcu_barrier_cpu_cnt, 1);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1183  
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1184  	if (!smp_load_acquire(&ssp->srcu_size_state)) {
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1185  		srcu_barrier_one_cpu(ssp, per_cpu_ptr(ssp->sda, 0));
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1186  	} else {
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1187  
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1188  		/*
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1189  		 * Each pass through this loop enqueues a callback, but only
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1190  		 * on CPUs already having callbacks enqueued.  Note that if
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1191  		 * a CPU already has callbacks enqueue, it must have already
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1192  		 * registered the need for a future grace period, so all we
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1193  		 * need do is enqueue a callback that will use the same
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1194  		 * grace period as the last callback already in the queue.
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1195  		 */
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1196  		for_each_possible_cpu(cpu) {
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1197  			sdp = per_cpu_ptr(ssp->sda, cpu);
2c773bcaf4dd50 Paul E. McKenney 2022-01-24  1198  			srcu_barrier_one_cpu(ssp, per_cpu_ptr(ssp->sda, cpu));
a602538e46c9c6 Paul E. McKenney 2017-04-28  1199  		}
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1200  	}
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1201  
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1202  	/* Remove the initial count, at which point reaching zero can happen. */
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1203  	if (atomic_dec_and_test(&ssp->srcu_barrier_cpu_cnt))
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1204  		complete(&ssp->srcu_barrier_completion);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1205  	wait_for_completion(&ssp->srcu_barrier_completion);
da915ad5cf25b5 Paul E. McKenney 2017-04-05  1206  
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1207  	rcu_seq_end(&ssp->srcu_barrier_seq);
aacb5d91ab1bfb Paul E. McKenney 2018-10-28  1208  	mutex_unlock(&ssp->srcu_barrier_mutex);
dad81a2026841b Paul E. McKenney 2017-03-25  1209  }
dad81a2026841b Paul E. McKenney 2017-03-25  1210  EXPORT_SYMBOL_GPL(srcu_barrier);
dad81a2026841b Paul E. McKenney 2017-03-25  1211  

:::::: The code at line 1168 was first introduced by commit
:::::: da915ad5cf25b5f5d358dd3670c3378d8ae8c03e srcu: Parallelize callback handling

:::::: TO: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
:::::: CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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2022-01-25 11:24 [ammarfaizi2-block:paulmck/linux-rcu/dev 80/85] kernel/rcu/srcutree.c:1168:27: warning: variable 'sdp' set but not used kernel test robot
2022-01-25 19:01 ` Paul E. McKenney
2022-01-25 11:34 kernel test robot

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