further BKL cleanups

diff -Nru a/arch/alpha/kernel/alpha_ksyms.c b/arch/alpha/kernel/alpha_ksyms.c
@@ -40,7 +40,6 @@
 extern struct hwrpb_struct *hwrpb;
 extern void dump_thread(struct pt_regs *, struct user *);
 extern int dump_fpu(struct pt_regs *, elf_fpregset_t *);
-extern spinlock_t kernel_flag;
 extern spinlock_t rtc_lock;
 
 /* these are C runtime functions with special calling conventions: */

@@ -207,7 +206,6 @@
  */
 
 #ifdef CONFIG_SMP
-EXPORT_SYMBOL(kernel_flag);
 EXPORT_SYMBOL(synchronize_irq);
 EXPORT_SYMBOL(flush_tlb_all);
 EXPORT_SYMBOL(flush_tlb_mm);

diff -Nru a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
@@ -67,8 +67,6 @@
 	IPI_CPU_STOP,
 };
 
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
-
 /* Set to a secondary's cpuid when it comes online.  */
 static int smp_secondary_alive __initdata = 0;
 

diff -Nru a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
@@ -273,7 +273,3 @@
 EXPORT_SYMBOL_NOVERS(__up_wakeup);
 
 EXPORT_SYMBOL(get_wchan);
-
-#ifdef CONFIG_PREEMPT
-EXPORT_SYMBOL(kernel_flag);
-#endif

diff -Nru a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
@@ -36,10 +36,6 @@
 #define MEM_SIZE	(16*1024*1024)
 #endif
 
-#ifdef CONFIG_PREEMPT
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
-#endif
-
 #if defined(CONFIG_FPE_NWFPE) || defined(CONFIG_FPE_FASTFPE)
 char fpe_type[8];
 

diff -Nru a/arch/i386/kernel/i386_ksyms.c b/arch/i386/kernel/i386_ksyms.c
@@ -126,7 +126,6 @@
 
 #ifdef CONFIG_SMP
 EXPORT_SYMBOL(cpu_data);
-EXPORT_SYMBOL(kernel_flag);
 EXPORT_SYMBOL(cpu_online_map);
 EXPORT_SYMBOL_NOVERS(__write_lock_failed);
 EXPORT_SYMBOL_NOVERS(__read_lock_failed);

diff -Nru a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c
@@ -18,6 +18,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/mc146818rtc.h>
 #include <linux/cache.h>
+#include <linux/interrupt.h>
 
 #include <asm/mtrr.h>
 #include <asm/pgalloc.h>

@@ -102,9 +103,6 @@
  *	or are signal timing bugs worked around in hardware and there's
  *	about nothing of note with C stepping upwards.
  */
-
-/* The 'big kernel lock' */
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
 
 struct tlb_state cpu_tlbstate[NR_CPUS] __cacheline_aligned = {[0 ... NR_CPUS-1] = { &init_mm, 0, }};
 

diff -Nru a/arch/ia64/kernel/ia64_ksyms.c b/arch/ia64/kernel/ia64_ksyms.c
@@ -84,10 +84,6 @@
 EXPORT_SYMBOL(smp_call_function_single);
 EXPORT_SYMBOL(cpu_online_map);
 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
-
-#include <asm/smplock.h>
-EXPORT_SYMBOL(kernel_flag);
-
 #else /* !CONFIG_SMP */
 
 EXPORT_SYMBOL(__flush_tlb_all);

diff -Nru a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c
@@ -53,14 +53,6 @@
 #include <asm/mca.h>
 
 /*
- * The Big Kernel Lock.  It's not supposed to be used for performance critical stuff
- * anymore.  But we still need to align it because certain workloads are still affected by
- * it.  For example, llseek() and various other filesystem related routines still use the
- * BKL.
- */
-spinlock_t kernel_flag __cacheline_aligned = SPIN_LOCK_UNLOCKED;
-
-/*
  * Structure and data for smp_call_function(). This is designed to minimise static memory
  * requirements. It also looks cleaner.
  */

diff -Nru a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
@@ -53,7 +53,6 @@
 
 
 /* Ze Big Kernel Lock! */
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
 int smp_threads_ready;  /* Not used */
 int smp_num_cpus;    
 int global_irq_holder = NO_PROC_ID;

diff -Nru a/arch/mips64/kernel/smp.c b/arch/mips64/kernel/smp.c
@@ -53,7 +53,6 @@
 #endif /* CONFIG_SGI_IP27 */
 
 /* The 'big kernel lock' */
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
 int smp_threads_ready;	/* Not used */
 atomic_t smp_commenced = ATOMIC_INIT(0);
 struct cpuinfo_mips cpu_data[NR_CPUS];

diff -Nru a/arch/parisc/kernel/parisc_ksyms.c b/arch/parisc/kernel/parisc_ksyms.c
@@ -35,9 +35,6 @@
 #ifdef CONFIG_SMP
 EXPORT_SYMBOL(synchronize_irq);
 
-#include <asm/smplock.h>
-EXPORT_SYMBOL(kernel_flag);
-
 #include <asm/system.h>
 EXPORT_SYMBOL(__global_sti);
 EXPORT_SYMBOL(__global_cli);

diff -Nru a/arch/ppc/kernel/ppc_ksyms.c b/arch/ppc/kernel/ppc_ksyms.c
@@ -93,9 +93,6 @@
 EXPORT_SYMBOL(disable_irq);
 EXPORT_SYMBOL(disable_irq_nosync);
 EXPORT_SYMBOL(probe_irq_mask);
-#ifdef CONFIG_SMP
-EXPORT_SYMBOL(kernel_flag);
-#endif /* CONFIG_SMP */
 
 EXPORT_SYMBOL(ISA_DMA_THRESHOLD);
 EXPORT_SYMBOL_NOVERS(DMA_MODE_READ);

diff -Nru a/arch/ppc/kernel/smp.c b/arch/ppc/kernel/smp.c
@@ -47,7 +47,6 @@
 struct klock_info_struct klock_info = { KLOCK_CLEAR, 0 };
 atomic_t ipi_recv;
 atomic_t ipi_sent;
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
 unsigned int prof_multiplier[NR_CPUS] = { [1 ... NR_CPUS-1] = 1 };
 unsigned int prof_counter[NR_CPUS] = { [1 ... NR_CPUS-1] = 1 };
 unsigned long cache_decay_ticks = HZ/100;

diff -Nru a/arch/ppc64/kernel/ppc_ksyms.c b/arch/ppc64/kernel/ppc_ksyms.c
@@ -74,7 +74,6 @@
 EXPORT_SYMBOL(disable_irq_nosync);
 #ifdef CONFIG_SMP
 EXPORT_SYMBOL(synchronize_irq);
-EXPORT_SYMBOL(kernel_flag);
 #endif /* CONFIG_SMP */
 
 EXPORT_SYMBOL(register_ioctl32_conversion);

diff -Nru a/arch/ppc64/kernel/smp.c b/arch/ppc64/kernel/smp.c
@@ -51,7 +51,6 @@
 #include <asm/machdep.h>
 
 int smp_threads_ready = 0;
-spinlock_t kernel_flag __cacheline_aligned = SPIN_LOCK_UNLOCKED;
 unsigned long cache_decay_ticks;
 
 /* initialised so it doesnt end up in bss */

diff -Nru a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
@@ -54,8 +54,6 @@
 int              smp_threads_ready=0;      /* Set when the idlers are all forked. */
 static atomic_t  smp_commenced = ATOMIC_INIT(0);
 
-spinlock_t       kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
-
 volatile unsigned long phys_cpu_present_map;
 volatile unsigned long cpu_online_map;
 unsigned long    cache_decay_ticks = 0;

@@ -634,7 +632,6 @@
 }
 
 EXPORT_SYMBOL(lowcore_ptr);
-EXPORT_SYMBOL(kernel_flag);
 EXPORT_SYMBOL(smp_ctl_set_bit);
 EXPORT_SYMBOL(smp_ctl_clear_bit);
 EXPORT_SYMBOL(smp_num_cpus);

diff -Nru a/arch/s390x/kernel/smp.c b/arch/s390x/kernel/smp.c
@@ -53,8 +53,6 @@
 int              smp_threads_ready=0;      /* Set when the idlers are all forked. */
 static atomic_t  smp_commenced = ATOMIC_INIT(0);
 
-spinlock_t       kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
-
 volatile unsigned long phys_cpu_present_map;
 volatile unsigned long cpu_online_map;
 unsigned long    cache_decay_ticks = 0;

@@ -613,7 +611,6 @@
 }
 
 EXPORT_SYMBOL(lowcore_ptr);
-EXPORT_SYMBOL(kernel_flag);
 EXPORT_SYMBOL(smp_ctl_set_bit);
 EXPORT_SYMBOL(smp_ctl_clear_bit);
 EXPORT_SYMBOL(smp_num_cpus);

diff -Nru a/arch/sparc/kernel/smp.c b/arch/sparc/kernel/smp.c
@@ -66,9 +66,6 @@
  * instruction which is much better...
  */
 
-/* Kernel spinlock */
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
-
 /* Used to make bitops atomic */
 unsigned char bitops_spinlock = 0;
 

diff -Nru a/arch/sparc/kernel/sparc_ksyms.c b/arch/sparc/kernel/sparc_ksyms.c
@@ -77,10 +77,6 @@
 
 extern void dump_thread(struct pt_regs *, struct user *);
 
-#ifdef CONFIG_SMP
-extern spinlock_t kernel_flag;
-#endif
-
 /* One thing to note is that the way the symbols of the mul/div
  * support routines are named is a mess, they all start with
  * a '.' which makes it a bitch to export, here is the trick:

@@ -130,9 +126,6 @@
 EXPORT_SYMBOL_PRIVATE(_change_bit);
 
 #ifdef CONFIG_SMP
-/* Kernel wide locking */
-EXPORT_SYMBOL(kernel_flag);
-
 /* IRQ implementation. */
 EXPORT_SYMBOL(global_irq_holder);
 EXPORT_SYMBOL(synchronize_irq);

diff -Nru a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
@@ -46,9 +46,6 @@
 /* Please don't make this stuff initdata!!!  --DaveM */
 static unsigned char boot_cpu_id;
 
-/* Kernel spinlock */
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
-
 atomic_t sparc64_num_cpus_online = ATOMIC_INIT(0);
 unsigned long cpu_online_map = 0;
 atomic_t sparc64_num_cpus_possible = ATOMIC_INIT(0);

diff -Nru a/arch/sparc64/kernel/sparc64_ksyms.c b/arch/sparc64/kernel/sparc64_ksyms.c
@@ -101,9 +101,7 @@
 extern void dump_thread(struct pt_regs *, struct user *);
 extern int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs);
 
-#ifdef CONFIG_SMP
-extern spinlock_t kernel_flag;
-#ifdef CONFIG_DEBUG_SPINLOCK
+#if defined(CONFIG_SMP) && defined(CONFIG_DEBUG_SPINLOCK)
 extern void _do_spin_lock (spinlock_t *lock, char *str);
 extern void _do_spin_unlock (spinlock_t *lock);
 extern int _spin_trylock (spinlock_t *lock);

@@ -112,7 +110,6 @@
 extern void _do_write_lock(rwlock_t *rw, char *str);
 extern void _do_write_unlock(rwlock_t *rw);
 #endif
-#endif
 
 extern unsigned long phys_base;
 extern unsigned long pfn_base;

@@ -126,9 +123,6 @@
 EXPORT_SYMBOL(__write_lock);
 EXPORT_SYMBOL(__write_unlock);
 #endif
-
-/* Kernel wide locking */
-EXPORT_SYMBOL(kernel_flag);
 
 /* Hard IRQ locking */
 #ifdef CONFIG_SMP

diff -Nru a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
@@ -22,9 +22,6 @@
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 
-/* The 'big kernel lock' */
-spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
-
 /*
  * the following functions deal with sending IPIs between CPUs.
  *

diff -Nru a/arch/x86_64/kernel/x8664_ksyms.c b/arch/x86_64/kernel/x8664_ksyms.c
@@ -109,7 +109,6 @@
 
 #ifdef CONFIG_SMP
 EXPORT_SYMBOL(cpu_data);
-EXPORT_SYMBOL(kernel_flag);
 EXPORT_SYMBOL(smp_num_cpus);
 EXPORT_SYMBOL(cpu_online_map);
 EXPORT_SYMBOL_NOVERS(__write_lock_failed);

94 lines not on this page · raw message

diff -Nru a/kernel/ksyms.c b/kernel/ksyms.c
@@ -51,6 +51,7 @@
 #include <linux/buffer_head.h>
 #include <linux/root_dev.h>
 #include <linux/percpu.h>
+#include <linux/smp_lock.h>
 #include <asm/checksum.h>
 
 #if defined(CONFIG_PROC_FS)

@@ -480,6 +481,9 @@
 EXPORT_SYMBOL_GPL(idle_cpu);
 #if CONFIG_SMP
 EXPORT_SYMBOL_GPL(set_cpus_allowed);
+#endif
+#if CONFIG_SMP || CONFIG_PREEMPT
+EXPORT_SYMBOL(kernel_flag);
 #endif
 EXPORT_SYMBOL(jiffies);
 EXPORT_SYMBOL(jiffies_64);

diff -Nru a/kernel/sched.c b/kernel/sched.c
@@ -1881,7 +1881,6 @@
 }
 
 #if CONFIG_SMP
-
 /*
  * This is how migration works:
  *

@@ -2068,6 +2067,20 @@
 	return 0;
 }
 
+#endif
+
+#if CONFIG_SMP || CONFIG_PREEMPT
+/*
+ * The 'big kernel lock'
+ *
+ * This spinlock is taken and released recursively by lock_kernel()
+ * and unlock_kernel().  It is transparently dropped and reaquired
+ * over schedule().  It is used to protect legacy code that hasn't
+ * been migrated to a proper locking design yet.
+ *
+ * Don't use in new code.
+ */
+spinlock_t kernel_flag __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
 #endif
 
 extern void init_timervecs(void);