diff mbox series

[3/9] rcu: Rename jiffies_till_flush to jiffies_lazy_flush

Message ID 20230531101736.12981-4-frederic@kernel.org (mailing list archive)
State New, archived
Headers show
Series rcu: Support for lazy callbacks on !CONFIG_RCU_NOCB_CPU | expand

Commit Message

Frederic Weisbecker May 31, 2023, 10:17 a.m. UTC 
The variable name jiffies_till_flush is too generic and therefore:

* It may shadow a global variable
* It doesn't tell on what it operates

Make the name more precise, along with the related APIs.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
 kernel/rcu/rcu.h       |  8 ++++----
 kernel/rcu/rcuscale.c  |  6 +++---
 kernel/rcu/tree_nocb.h | 20 ++++++++++----------
 3 files changed, 17 insertions(+), 17 deletions(-)

Comments

kernel test robot June 1, 2023, 5:15 p.m. UTC | #1 
Hi Frederic,

kernel test robot noticed the following build warnings:

[auto build test WARNING on paulmck-rcu/dev]
[also build test WARNING on linus/master v6.4-rc4 next-20230601]
[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/Frederic-Weisbecker/rcu-Assume-IRQS-disabled-from-rcu_report_dead/20230531-182004
base:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
patch link:    https://lore.kernel.org/r/20230531101736.12981-4-frederic%40kernel.org
patch subject: [PATCH 3/9] rcu: Rename jiffies_till_flush to jiffies_lazy_flush
config: arc-allyesconfig (https://download.01.org/0day-ci/archive/20230602/202306020130.M1c0QAFE-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 12.3.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        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/c07a1bea9df8b80429d4e24052d83de94f5ee160
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Frederic-Weisbecker/rcu-Assume-IRQS-disabled-from-rcu_report_dead/20230531-182004
        git checkout c07a1bea9df8b80429d4e24052d83de94f5ee160
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=arc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash kernel/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306020130.M1c0QAFE-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from kernel/rcu/tree.c:5018:
>> kernel/rcu/tree_nocb.h:271:6: warning: no previous prototype for 'rcu_lazy_set_jiffies_lazy_flush' [-Wmissing-prototypes]
     271 | void rcu_lazy_set_jiffies_lazy_flush(unsigned long jif)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> kernel/rcu/tree_nocb.h:277:15: warning: no previous prototype for 'rcu_lazy_get_jiffies_lazy_flush' [-Wmissing-prototypes]
     277 | unsigned long rcu_lazy_get_jiffies_lazy_flush(void)
         |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/rcu_lazy_set_jiffies_lazy_flush +271 kernel/rcu/tree_nocb.h

   268	
   269	#ifdef CONFIG_RCU_LAZY
   270	// To be called only from test code.
 > 271	void rcu_lazy_set_jiffies_lazy_flush(unsigned long jif)
   272	{
   273		jiffies_lazy_flush = jif;
   274	}
   275	EXPORT_SYMBOL(rcu_lazy_set_jiffies_lazy_flush);
   276	
 > 277	unsigned long rcu_lazy_get_jiffies_lazy_flush(void)
   278	{
   279		return jiffies_lazy_flush;
   280	}
   281	EXPORT_SYMBOL(rcu_lazy_get_jiffies_lazy_flush);
   282	#endif
   283
kernel test robot June 1, 2023, 5:15 p.m. UTC | #2 
Hi Frederic,

kernel test robot noticed the following build errors:

[auto build test ERROR on paulmck-rcu/dev]
[also build test ERROR on linus/master v6.4-rc4 next-20230601]
[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/Frederic-Weisbecker/rcu-Assume-IRQS-disabled-from-rcu_report_dead/20230531-182004
base:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
patch link:    https://lore.kernel.org/r/20230531101736.12981-4-frederic%40kernel.org
patch subject: [PATCH 3/9] rcu: Rename jiffies_till_flush to jiffies_lazy_flush
config: mips-allmodconfig (https://download.01.org/0day-ci/archive/20230602/202306020110.p6f7zsig-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 12.3.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        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/c07a1bea9df8b80429d4e24052d83de94f5ee160
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Frederic-Weisbecker/rcu-Assume-IRQS-disabled-from-rcu_report_dead/20230531-182004
        git checkout c07a1bea9df8b80429d4e24052d83de94f5ee160
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=mips olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306020110.p6f7zsig-lkp@intel.com/

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "rcu_get_jiffies_lazy_flush" [kernel/rcu/rcuscale.ko] undefined!
>> ERROR: modpost: "rcu_set_jiffies_lazy_flush" [kernel/rcu/rcuscale.ko] undefined!
kernel test robot June 1, 2023, 10:40 p.m. UTC | #3 
Hi Frederic,

kernel test robot noticed the following build errors:

[auto build test ERROR on paulmck-rcu/dev]
[also build test ERROR on linus/master v6.4-rc4 next-20230601]
[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/Frederic-Weisbecker/rcu-Assume-IRQS-disabled-from-rcu_report_dead/20230531-182004
base:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
patch link:    https://lore.kernel.org/r/20230531101736.12981-4-frederic%40kernel.org
patch subject: [PATCH 3/9] rcu: Rename jiffies_till_flush to jiffies_lazy_flush
config: arm-allyesconfig (https://download.01.org/0day-ci/archive/20230602/202306020646.Ud0VLSIi-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 12.3.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        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/c07a1bea9df8b80429d4e24052d83de94f5ee160
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Frederic-Weisbecker/rcu-Assume-IRQS-disabled-from-rcu_report_dead/20230531-182004
        git checkout c07a1bea9df8b80429d4e24052d83de94f5ee160
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306020646.Ud0VLSIi-lkp@intel.com/

All errors (new ones prefixed by >>):

   arm-linux-gnueabi-ld: kernel/rcu/rcuscale.o: in function `kfree_scale_init':
   rcuscale.c:(.init.text+0xec): undefined reference to `rcu_get_jiffies_lazy_flush'
>> arm-linux-gnueabi-ld: rcuscale.c:(.init.text+0x104): undefined reference to `rcu_set_jiffies_lazy_flush'
   arm-linux-gnueabi-ld: rcuscale.c:(.init.text+0x170): undefined reference to `rcu_set_jiffies_lazy_flush'
diff mbox series

Patch

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 98c1544cf572..236d6f837c49 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -526,11 +526,11 @@  enum rcutorture_type {
 };
 
 #if defined(CONFIG_RCU_LAZY)
-unsigned long rcu_lazy_get_jiffies_till_flush(void);
-void rcu_lazy_set_jiffies_till_flush(unsigned long j);
+unsigned long rcu_get_jiffies_lazy_flush(void);
+void rcu_set_jiffies_lazy_flush(unsigned long j);
 #else
-static inline unsigned long rcu_lazy_get_jiffies_till_flush(void) { return 0; }
-static inline void rcu_lazy_set_jiffies_till_flush(unsigned long j) { }
+static inline unsigned long rcu_get_jiffies_lazy_flush(void) { return 0; }
+static inline void rcu_set_jiffies_lazy_flush(unsigned long j) { }
 #endif
 
 #if defined(CONFIG_TREE_RCU)
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 7fba3ab66e35..53ec80868791 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -725,9 +725,9 @@  kfree_scale_init(void)
 
 	if (kfree_by_call_rcu) {
 		/* do a test to check the timeout. */
-		orig_jif = rcu_lazy_get_jiffies_till_flush();
+		orig_jif = rcu_get_jiffies_lazy_flush();
 
-		rcu_lazy_set_jiffies_till_flush(2 * HZ);
+		rcu_set_jiffies_lazy_flush(2 * HZ);
 		rcu_barrier();
 
 		jif_start = jiffies;
@@ -736,7 +736,7 @@  kfree_scale_init(void)
 
 		smp_cond_load_relaxed(&rcu_lazy_test1_cb_called, VAL == 1);
 
-		rcu_lazy_set_jiffies_till_flush(orig_jif);
+		rcu_set_jiffies_lazy_flush(orig_jif);
 
 		if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start < 2 * HZ)) {
 			pr_alert("ERROR: call_rcu() CBs are not being lazy as expected!\n");
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 43229d2b0c44..8320eb77b58b 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -264,21 +264,21 @@  static bool wake_nocb_gp(struct rcu_data *rdp, bool force)
  * left unsubmitted to RCU after those many jiffies.
  */
 #define LAZY_FLUSH_JIFFIES (10 * HZ)
-static unsigned long jiffies_till_flush = LAZY_FLUSH_JIFFIES;
+static unsigned long jiffies_lazy_flush = LAZY_FLUSH_JIFFIES;
 
 #ifdef CONFIG_RCU_LAZY
 // To be called only from test code.
-void rcu_lazy_set_jiffies_till_flush(unsigned long jif)
+void rcu_lazy_set_jiffies_lazy_flush(unsigned long jif)
 {
-	jiffies_till_flush = jif;
+	jiffies_lazy_flush = jif;
 }
-EXPORT_SYMBOL(rcu_lazy_set_jiffies_till_flush);
+EXPORT_SYMBOL(rcu_lazy_set_jiffies_lazy_flush);
 
-unsigned long rcu_lazy_get_jiffies_till_flush(void)
+unsigned long rcu_lazy_get_jiffies_lazy_flush(void)
 {
-	return jiffies_till_flush;
+	return jiffies_lazy_flush;
 }
-EXPORT_SYMBOL(rcu_lazy_get_jiffies_till_flush);
+EXPORT_SYMBOL(rcu_lazy_get_jiffies_lazy_flush);
 #endif
 
 /*
@@ -299,7 +299,7 @@  static void wake_nocb_gp_defer(struct rcu_data *rdp, int waketype,
 	 */
 	if (waketype == RCU_NOCB_WAKE_LAZY &&
 	    rdp->nocb_defer_wakeup == RCU_NOCB_WAKE_NOT) {
-		mod_timer(&rdp_gp->nocb_timer, jiffies + jiffies_till_flush);
+		mod_timer(&rdp_gp->nocb_timer, jiffies + jiffies_lazy_flush);
 		WRITE_ONCE(rdp_gp->nocb_defer_wakeup, waketype);
 	} else if (waketype == RCU_NOCB_WAKE_BYPASS) {
 		mod_timer(&rdp_gp->nocb_timer, jiffies + 2);
@@ -482,7 +482,7 @@  static bool rcu_nocb_try_bypass(struct rcu_data *rdp, struct rcu_head *rhp,
 	// flush ->nocb_bypass to ->cblist.
 	if ((ncbs && !bypass_is_lazy && j != READ_ONCE(rdp->nocb_bypass_first)) ||
 	    (ncbs &&  bypass_is_lazy &&
-	     (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + jiffies_till_flush))) ||
+	     (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + jiffies_lazy_flush))) ||
 	    ncbs >= qhimark) {
 		rcu_nocb_lock(rdp);
 		*was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist);
@@ -723,7 +723,7 @@  static void nocb_gp_wait(struct rcu_data *my_rdp)
 		lazy_ncbs = READ_ONCE(rdp->lazy_len);
 
 		if (bypass_ncbs && (lazy_ncbs == bypass_ncbs) &&
-		    (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + jiffies_till_flush) ||
+		    (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + jiffies_lazy_flush) ||
 		     bypass_ncbs > 2 * qhimark)) {
 			flush_bypass = true;
 		} else if (bypass_ncbs && (lazy_ncbs != bypass_ncbs) &&