ia64/tlb: Eradicate tlb_migrate_finish() callback

Only ia64-sn2 uses this as an optimization, and there it is of
questionable correctness due to the mm_users==1 test.

Remove it entirely.

No change in behavior intended.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/Documentation/core-api/cachetlb.rst b/Documentation/core-api/cachetlb.rst
index 6eb9d3f090cdf5d9a82afa3bd46cec5554ca116a..93cb65d52720a0ef72b2ba527ef3135b579c113e 100644 (file)
--- a/Documentation/core-api/cachetlb.rst
+++ b/Documentation/core-api/cachetlb.rst
@@ -101,16 +101,6 @@ changes occur:
        translations for software managed TLB configurations.
        The sparc64 port currently does this.
 
-6) ``void tlb_migrate_finish(struct mm_struct *mm)``
-
-       This interface is called at the end of an explicit
-       process migration. This interface provides a hook
-       to allow a platform to update TLB or context-specific
-       information for the address space.
-
-       The ia64 sn2 platform is one example of a platform
-       that uses this interface.
-
 Next, we have the cache flushing interfaces.  In general, when Linux
 is changing an existing virtual-->physical mapping to a new value,
 the sequence will be in one of the following forms::

diff --git a/arch/ia64/include/asm/machvec.h b/arch/ia64/include/asm/machvec.h
index 5133739966bcfa00570aca667c88d96fe71e771a..beae261fbcb415b2321af6c333bd9ce5e304896f 100644 (file)
--- a/arch/ia64/include/asm/machvec.h
+++ b/arch/ia64/include/asm/machvec.h
@@ -30,7 +30,6 @@ typedef void ia64_mv_irq_init_t (void);
 typedef void ia64_mv_send_ipi_t (int, int, int, int);
 typedef void ia64_mv_timer_interrupt_t (int, void *);
 typedef void ia64_mv_global_tlb_purge_t (struct mm_struct *, unsigned long, unsigned long, unsigned long);
-typedef void ia64_mv_tlb_migrate_finish_t (struct mm_struct *);
 typedef u8 ia64_mv_irq_to_vector (int);
 typedef unsigned int ia64_mv_local_vector_to_irq (u8);
 typedef char *ia64_mv_pci_get_legacy_mem_t (struct pci_bus *);
@@ -79,11 +78,6 @@ machvec_noop (void)
 {
 }
 
-static inline void
-machvec_noop_mm (struct mm_struct *mm)
-{
-}
-
 static inline void
 machvec_noop_task (struct task_struct *task)
 {
@@ -96,7 +90,6 @@ machvec_noop_bus (struct pci_bus *bus)
 
 extern void machvec_setup (char **);
 extern void machvec_timer_interrupt (int, void *);
-extern void machvec_tlb_migrate_finish (struct mm_struct *);
 
 # if defined (CONFIG_IA64_HP_SIM)
 #  include <asm/machvec_hpsim.h>
@@ -124,7 +117,6 @@ extern void machvec_tlb_migrate_finish (struct mm_struct *);
 #  define platform_send_ipi    ia64_mv.send_ipi
 #  define platform_timer_interrupt     ia64_mv.timer_interrupt
 #  define platform_global_tlb_purge    ia64_mv.global_tlb_purge
-#  define platform_tlb_migrate_finish  ia64_mv.tlb_migrate_finish
 #  define platform_dma_init            ia64_mv.dma_init
 #  define platform_dma_get_ops         ia64_mv.dma_get_ops
 #  define platform_irq_to_vector       ia64_mv.irq_to_vector
@@ -167,7 +159,6 @@ struct ia64_machine_vector {
        ia64_mv_send_ipi_t *send_ipi;
        ia64_mv_timer_interrupt_t *timer_interrupt;
        ia64_mv_global_tlb_purge_t *global_tlb_purge;
-       ia64_mv_tlb_migrate_finish_t *tlb_migrate_finish;
        ia64_mv_dma_init *dma_init;
        ia64_mv_dma_get_ops *dma_get_ops;
        ia64_mv_irq_to_vector *irq_to_vector;
@@ -206,7 +197,6 @@ struct ia64_machine_vector {
        platform_send_ipi,                      \
        platform_timer_interrupt,               \
        platform_global_tlb_purge,              \
-       platform_tlb_migrate_finish,            \
        platform_dma_init,                      \
        platform_dma_get_ops,                   \
        platform_irq_to_vector,                 \
@@ -270,9 +260,6 @@ extern const struct dma_map_ops *dma_get_ops(struct device *);
 #ifndef platform_global_tlb_purge
 # define platform_global_tlb_purge     ia64_global_tlb_purge /* default to architected version */
 #endif
-#ifndef platform_tlb_migrate_finish
-# define platform_tlb_migrate_finish   machvec_noop_mm
-#endif
 #ifndef platform_kernel_launch_event
 # define platform_kernel_launch_event  machvec_noop
 #endif

diff --git a/arch/ia64/include/asm/machvec_sn2.h b/arch/ia64/include/asm/machvec_sn2.h
index b5153d300289724622ae936d560b40a94e471500..a243e4fb4877d7416949359ae6b52d59d25d803d 100644 (file)
--- a/arch/ia64/include/asm/machvec_sn2.h
+++ b/arch/ia64/include/asm/machvec_sn2.h
@@ -34,7 +34,6 @@ extern ia64_mv_irq_init_t sn_irq_init;
 extern ia64_mv_send_ipi_t sn2_send_IPI;
 extern ia64_mv_timer_interrupt_t sn_timer_interrupt;
 extern ia64_mv_global_tlb_purge_t sn2_global_tlb_purge;
-extern ia64_mv_tlb_migrate_finish_t    sn_tlb_migrate_finish;
 extern ia64_mv_irq_to_vector sn_irq_to_vector;
 extern ia64_mv_local_vector_to_irq sn_local_vector_to_irq;
 extern ia64_mv_pci_get_legacy_mem_t sn_pci_get_legacy_mem;
@@ -77,7 +76,6 @@ extern ia64_mv_pci_fixup_bus_t                sn_pci_fixup_bus;
 #define platform_send_ipi              sn2_send_IPI
 #define platform_timer_interrupt       sn_timer_interrupt
 #define platform_global_tlb_purge       sn2_global_tlb_purge
-#define platform_tlb_migrate_finish    sn_tlb_migrate_finish
 #define platform_pci_fixup             sn_pci_fixup
 #define platform_inb                   __sn_inb
 #define platform_inw                   __sn_inw

diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h
index 849fab9ccb33338175a3a869d514ff439fbb14c0..86ec034ba49917bcc2b71b8425ffdafd82ed1cae 100644 (file)
--- a/arch/ia64/include/asm/tlb.h
+++ b/arch/ia64/include/asm/tlb.h
@@ -47,8 +47,6 @@
 #include <asm/tlbflush.h>
 #include <asm/machvec.h>
 
-#define tlb_migrate_finish(mm) platform_tlb_migrate_finish(mm)
-
 #include <asm-generic/tlb.h>
 
 #endif /* _ASM_IA64_TLB_H */

diff --git a/arch/ia64/sn/kernel/sn2/sn2_smp.c b/arch/ia64/sn/kernel/sn2/sn2_smp.c
index b73b0ebf82148eac5442a55eeb5f40a3e35897f9..b510f4f17fd4679abf2e0de1fd5191f6f56d5a8f 100644 (file)
--- a/arch/ia64/sn/kernel/sn2/sn2_smp.c
+++ b/arch/ia64/sn/kernel/sn2/sn2_smp.c
@@ -120,13 +120,6 @@ void sn_migrate(struct task_struct *task)
                cpu_relax();
 }
 
-void sn_tlb_migrate_finish(struct mm_struct *mm)
-{
-       /* flush_tlb_mm is inefficient if more than 1 users of mm */
-       if (mm == current->mm && mm && atomic_read(&mm->mm_users) == 1)
-               flush_tlb_mm(mm);
-}
-
 static void
 sn2_ipi_flush_all_tlb(struct mm_struct *mm)
 {

diff --git a/arch/nds32/include/asm/tlbflush.h b/arch/nds32/include/asm/tlbflush.h
index 9b411f401903630fff9f66498e09a6f1f1f7ce3e..38ee769b18d8ad344e09819dff0fb93c24af94bc 100644 (file)
--- a/arch/nds32/include/asm/tlbflush.h
+++ b/arch/nds32/include/asm/tlbflush.h
@@ -42,6 +42,5 @@ void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long addr);
 
 void update_mmu_cache(struct vm_area_struct *vma,
                      unsigned long address, pte_t * pte);
-void tlb_migrate_finish(struct mm_struct *mm);
 
 #endif

diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index fc661b4675ffa92e24567e0defa9609d4ea05605..b9edc7608d9019db11ae45088bbb9cbcd75ca168 100644 (file)
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -604,8 +604,4 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
 
 #endif /* CONFIG_MMU */
 
-#ifndef tlb_migrate_finish
-#define tlb_migrate_finish(mm) do {} while (0)
-#endif
-
 #endif /* _ASM_GENERIC__TLB_H */

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4778c48a7fda4d78cd1dbff0afa658f82da38ba1..ade3f2287d1f69d9f4362015f618d4c8128de8b5 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1151,7 +1151,6 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
                /* Need help from migration thread: drop lock and wait. */
                task_rq_unlock(rq, p, &rf);
                stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
-               tlb_migrate_finish(p->mm);
                return 0;
        } else if (task_on_rq_queued(p)) {
                /*