From: Liam R. Howlett Date: Mon, 16 Nov 2020 19:50:20 +0000 (-0500) Subject: mm: Remove vmacache X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4762f5069a6120d1ae4f6a664092b3978bce8dfe;p=users%2Fjedix%2Flinux-maple.git mm: Remove vmacache By using the maple tree and the maple tree state, the vmacache is no longer beneficial and is complicating the VMA code. Remove the vmacache to reduce the work in keeping it up to date and code complexity. Signed-off-by: Liam R. Howlett --- diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig index 86afcc6b56bf..f754bf711261 100644 --- a/arch/s390/configs/debug_defconfig +++ b/arch/s390/configs/debug_defconfig @@ -791,7 +791,6 @@ CONFIG_SLUB_DEBUG_ON=y CONFIG_SLUB_STATS=y CONFIG_DEBUG_STACK_USAGE=y CONFIG_DEBUG_VM=y -CONFIG_DEBUG_VM_VMACACHE=y CONFIG_DEBUG_VM_PGFLAGS=y CONFIG_DEBUG_MEMORY_INIT=y CONFIG_MEMORY_NOTIFIER_ERROR_INJECT=m diff --git a/fs/exec.c b/fs/exec.c index 38f63451b928..3dfa1e6d237f 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -28,7 +28,6 @@ #include #include #include -#include #include #include #include @@ -1017,8 +1016,6 @@ static int exec_mmap(struct mm_struct *mm) activate_mm(active_mm, mm); if (IS_ENABLED(CONFIG_ARCH_WANT_IRQS_OFF_ACTIVATE_MM)) local_irq_enable(); - tsk->mm->vmacache_seqnum = 0; - vmacache_flush(tsk); task_unlock(tsk); if (old_mm) { mmap_read_unlock(old_mm); diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index eb97468dfe4c..ab9b4ff44b54 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include #include #include #include diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 55635e04376f..15304a3deb28 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -380,7 +380,6 @@ struct mm_struct { struct { struct vm_area_struct *mmap; /* list of VMAs */ struct maple_tree mm_mt; - u64 vmacache_seqnum; /* per-thread vmacache */ #ifdef CONFIG_MMU unsigned long (*get_unmapped_area) (struct file *filp, unsigned long addr, unsigned long len, diff --git a/include/linux/mm_types_task.h b/include/linux/mm_types_task.h index 1b222f8039d1..418ec7df5f18 100644 --- a/include/linux/mm_types_task.h +++ b/include/linux/mm_types_task.h @@ -36,11 +36,6 @@ #define VMACACHE_SIZE (1U << VMACACHE_BITS) #define VMACACHE_MASK (VMACACHE_SIZE - 1) -struct vmacache { - u64 seqnum; - struct vm_area_struct *vmas[VMACACHE_SIZE]; -}; - /* * When updating this, please also update struct resident_page_types[] in * kernel/fork.c diff --git a/include/linux/sched.h b/include/linux/sched.h index 38145174c7b1..5b4e2c888353 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -779,7 +779,6 @@ struct task_struct { struct mm_struct *active_mm; /* Per-thread vma caching: */ - struct vmacache vmacache; #ifdef SPLIT_RSS_COUNTING struct task_rss_stat rss_stat; diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index ae0dd1948c2b..cd3ff075470b 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -117,10 +117,6 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, NR_TLB_LOCAL_FLUSH_ALL, NR_TLB_LOCAL_FLUSH_ONE, #endif /* CONFIG_DEBUG_TLBFLUSH */ -#ifdef CONFIG_DEBUG_VM_VMACACHE - VMACACHE_FIND_CALLS, - VMACACHE_FIND_HITS, -#endif #ifdef CONFIG_SWAP SWAP_RA, SWAP_RA_HIT, diff --git a/include/linux/vmacache.h b/include/linux/vmacache.h deleted file mode 100644 index 6fce268a4588..000000000000 --- a/include/linux/vmacache.h +++ /dev/null @@ -1,28 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef __LINUX_VMACACHE_H -#define __LINUX_VMACACHE_H - -#include -#include - -static inline void vmacache_flush(struct task_struct *tsk) -{ - memset(tsk->vmacache.vmas, 0, sizeof(tsk->vmacache.vmas)); -} - -extern void vmacache_update(unsigned long addr, struct vm_area_struct *newvma); -extern struct vm_area_struct *vmacache_find(struct mm_struct *mm, - unsigned long addr); - -#ifndef CONFIG_MMU -extern struct vm_area_struct *vmacache_find_exact(struct mm_struct *mm, - unsigned long start, - unsigned long end); -#endif - -static inline void vmacache_invalidate(struct mm_struct *mm) -{ - mm->vmacache_seqnum++; -} - -#endif /* __LINUX_VMACACHE_H */ diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index d6a6cf53b127..f9a2924a2174 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -125,12 +125,6 @@ static inline void vm_events_fold_cpu(int cpu) #define count_vm_tlb_events(x, y) do { (void)(y); } while (0) #endif -#ifdef CONFIG_DEBUG_VM_VMACACHE -#define count_vm_vmacache_event(x) count_vm_event(x) -#else -#define count_vm_vmacache_event(x) do {} while (0) -#endif - #define __count_zid_vm_events(item, zid, delta) \ __count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta) diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 4708aec492df..1bd0bb76ed2c 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -53,7 +53,6 @@ #include #include #include -#include #include #include @@ -285,17 +284,6 @@ static void kgdb_flush_swbreak_addr(unsigned long addr) if (!CACHE_FLUSH_IS_SAFE) return; - if (current->mm) { - int i; - - for (i = 0; i < VMACACHE_SIZE; i++) { - if (!current->vmacache.vmas[i]) - continue; - flush_cache_range(current->vmacache.vmas[i], - addr, addr + BREAK_INSTR_SIZE); - } - } - /* Force flush instruction cache if it was outside the mm */ flush_icache_range(addr, addr + BREAK_INSTR_SIZE); } diff --git a/kernel/fork.c b/kernel/fork.c index 08db38b8984c..ab5f47754ca6 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -42,7 +42,6 @@ #include #include #include -#include #include #include #include @@ -1042,7 +1041,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, { mm->mmap = NULL; mt_init_flags(&mm->mm_mt, MAPLE_ALLOC_RANGE); - mm->vmacache_seqnum = 0; atomic_set(&mm->mm_users, 1); atomic_set(&mm->mm_count, 1); seqcount_init(&mm->write_protect_seq); @@ -1439,9 +1437,6 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk) if (!oldmm) return 0; - /* initialize the new vmacache entries */ - vmacache_flush(tsk); - if (clone_flags & CLONE_VM) { mmget(oldmm); mm = oldmm; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 863cb6a62c17..c54365c53578 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -803,16 +803,6 @@ config DEBUG_VM If unsure, say N. -config DEBUG_VM_VMACACHE - bool "Debug VMA caching" - depends on DEBUG_VM - help - Enable this to turn on VMA caching debug information. Doing so - can cause significant overhead, so only enable it in non-production - environments. - - If unsure, say N. - config DEBUG_VM_RB bool "Debug VM red-black trees" depends on DEBUG_VM diff --git a/mm/Makefile b/mm/Makefile index e3436741d539..0cd70dcd75a9 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -50,7 +50,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ readahead.o swap.o truncate.o vmscan.o shmem.o \ util.o mmzone.o vmstat.o backing-dev.o \ mm_init.o percpu.o slab_common.o \ - compaction.o vmacache.o \ + compaction.o \ interval_tree.o list_lru.o workingset.o \ debug.o gup.o mmap_lock.o $(mmu-y) diff --git a/mm/debug.c b/mm/debug.c index e73fe0a8ec3d..f84662c87b4f 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -203,7 +203,7 @@ EXPORT_SYMBOL(dump_vma); void dump_mm(const struct mm_struct *mm) { - pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n" + pr_emerg("mm %px mmap %px task_size %lu\n" #ifdef CONFIG_MMU "get_unmapped_area %px\n" #endif @@ -231,7 +231,7 @@ void dump_mm(const struct mm_struct *mm) "tlb_flush_pending %d\n" "def_flags: %#lx(%pGv)\n", - mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size, + mm, mm->mmap, mm->task_size, #ifdef CONFIG_MMU mm->get_unmapped_area, #endif diff --git a/mm/mmap.c b/mm/mmap.c index f9209d9145be..48fd97f3d7ae 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -13,7 +13,6 @@ #include #include #include -#include #include #include #include @@ -712,9 +711,6 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma, /* Remove from mm linked list - also updates highest_vm_end */ __vma_unlink_list(mm, next); - /* Kill the cache */ - vmacache_invalidate(mm); - if (file) __remove_shared_vm_struct(next, file, mapping); @@ -929,8 +925,6 @@ again: if (remove_next) { __vma_unlink_list(mm, next); - /* Kill the cache */ - vmacache_invalidate(mm); if (file) __remove_shared_vm_struct(next, file, mapping); } else if (insert) { @@ -2225,16 +2219,9 @@ struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, struct vm_area_struct *vma; MA_STATE(mas, &mm->mm_mt, start_addr, start_addr); - /* Check the cache first. */ - vma = vmacache_find(mm, start_addr); - if (likely(vma)) - return vma; - rcu_read_lock(); vma = mas_find(&mas, end_addr - 1); rcu_read_unlock(); - if (vma) - vmacache_update(mas.index, vma); return vma; } @@ -2627,9 +2614,6 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma, mm->highest_vm_end = prev ? vm_end_gap(prev) : 0; tail_vma->vm_next = NULL; - /* Kill the cache */ - vmacache_invalidate(mm); - /* * Do not downgrade mmap_lock if we are next to VM_GROWSDOWN or * VM_GROWSUP VMA. Such VMAs can change their size under @@ -3009,7 +2993,6 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma, if (vma_mas_remove(&unmap, mas)) goto mas_store_fail; - vmacache_invalidate(vma->vm_mm); if (vma->anon_vma) { anon_vma_interval_tree_post_update_vma(vma); anon_vma_unlock_write(vma->anon_vma); diff --git a/mm/nommu.c b/mm/nommu.c index eac5ca450bef..675aee78f8f2 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -19,7 +19,6 @@ #include #include #include -#include #include #include #include @@ -586,22 +585,12 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) */ static void delete_vma_from_mm(struct vm_area_struct *vma) { - int i; - struct address_space *mapping; - struct mm_struct *mm = vma->vm_mm; - struct task_struct *curr = current; MA_STATE(mas, &vma->vm_mm->mm_mt, 0, 0); - mm->map_count--; - for (i = 0; i < VMACACHE_SIZE; i++) { - /* if the vma is cached, invalidate the entire cache */ - if (curr->vmacache.vmas[i] == vma) { - vmacache_invalidate(mm); - break; - } - } + vma->vm_mm->map_count--; /* remove the VMA from the mapping */ if (vma->vm_file) { + struct address_space *mapping; mapping = vma->vm_file->f_mapping; i_mmap_lock_write(mapping); @@ -613,7 +602,7 @@ static void delete_vma_from_mm(struct vm_area_struct *vma) /* remove from the MM's tree and list */ vma_mas_remove(vma, &mas); - __vma_unlink_list(mm, vma); + __vma_unlink_list(vma->vm_mm, vma); } /* @@ -638,18 +627,10 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) struct vm_area_struct *vma; MA_STATE(mas, &mm->mm_mt, addr, addr); - /* check the cache first */ - vma = vmacache_find(mm, addr); - if (likely(vma)) - return vma; - rcu_read_lock(); vma = mas_walk(&mas); rcu_read_unlock(); - if (vma) - vmacache_update(addr, vma); - return vma; } EXPORT_SYMBOL(find_vma); @@ -684,11 +665,6 @@ static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, unsigned long end = addr + len; MA_STATE(mas, &mm->mm_mt, addr, addr); - /* check the cache first */ - vma = vmacache_find_exact(mm, addr, end); - if (vma) - return vma; - rcu_read_lock(); vma = mas_walk(&mas); rcu_read_unlock(); @@ -699,7 +675,6 @@ static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, if (vma->vm_end != end) return NULL; - vmacache_update(addr, vma); return vma; } diff --git a/mm/vmacache.c b/mm/vmacache.c deleted file mode 100644 index 01a6e6688ec1..000000000000 --- a/mm/vmacache.c +++ /dev/null @@ -1,117 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Copyright (C) 2014 Davidlohr Bueso. - */ -#include -#include -#include -#include - -/* - * Hash based on the pmd of addr if configured with MMU, which provides a good - * hit rate for workloads with spatial locality. Otherwise, use pages. - */ -#ifdef CONFIG_MMU -#define VMACACHE_SHIFT PMD_SHIFT -#else -#define VMACACHE_SHIFT PAGE_SHIFT -#endif -#define VMACACHE_HASH(addr) ((addr >> VMACACHE_SHIFT) & VMACACHE_MASK) - -/* - * This task may be accessing a foreign mm via (for example) - * get_user_pages()->find_vma(). The vmacache is task-local and this - * task's vmacache pertains to a different mm (ie, its own). There is - * nothing we can do here. - * - * Also handle the case where a kernel thread has adopted this mm via - * kthread_use_mm(). That kernel thread's vmacache is not applicable to this mm. - */ -static inline bool vmacache_valid_mm(struct mm_struct *mm) -{ - return current->mm == mm && !(current->flags & PF_KTHREAD); -} - -void vmacache_update(unsigned long addr, struct vm_area_struct *newvma) -{ - if (vmacache_valid_mm(newvma->vm_mm)) - current->vmacache.vmas[VMACACHE_HASH(addr)] = newvma; -} - -static bool vmacache_valid(struct mm_struct *mm) -{ - struct task_struct *curr; - - if (!vmacache_valid_mm(mm)) - return false; - - curr = current; - if (mm->vmacache_seqnum != curr->vmacache.seqnum) { - /* - * First attempt will always be invalid, initialize - * the new cache for this task here. - */ - curr->vmacache.seqnum = mm->vmacache_seqnum; - vmacache_flush(curr); - return false; - } - return true; -} - -struct vm_area_struct *vmacache_find(struct mm_struct *mm, unsigned long addr) -{ - int idx = VMACACHE_HASH(addr); - int i; - - count_vm_vmacache_event(VMACACHE_FIND_CALLS); - - if (!vmacache_valid(mm)) - return NULL; - - for (i = 0; i < VMACACHE_SIZE; i++) { - struct vm_area_struct *vma = current->vmacache.vmas[idx]; - - if (vma) { -#ifdef CONFIG_DEBUG_VM_VMACACHE - if (WARN_ON_ONCE(vma->vm_mm != mm)) - break; -#endif - if (vma->vm_start <= addr && vma->vm_end > addr) { - count_vm_vmacache_event(VMACACHE_FIND_HITS); - return vma; - } - } - if (++idx == VMACACHE_SIZE) - idx = 0; - } - - return NULL; -} - -#ifndef CONFIG_MMU -struct vm_area_struct *vmacache_find_exact(struct mm_struct *mm, - unsigned long start, - unsigned long end) -{ - int idx = VMACACHE_HASH(start); - int i; - - count_vm_vmacache_event(VMACACHE_FIND_CALLS); - - if (!vmacache_valid(mm)) - return NULL; - - for (i = 0; i < VMACACHE_SIZE; i++) { - struct vm_area_struct *vma = current->vmacache.vmas[idx]; - - if (vma && vma->vm_start == start && vma->vm_end == end) { - count_vm_vmacache_event(VMACACHE_FIND_HITS); - return vma; - } - if (++idx == VMACACHE_SIZE) - idx = 0; - } - - return NULL; -} -#endif diff --git a/mm/vmstat.c b/mm/vmstat.c index b0534e068166..651ab5cc00e0 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1319,10 +1319,6 @@ const char * const vmstat_text[] = { "nr_tlb_local_flush_one", #endif /* CONFIG_DEBUG_TLBFLUSH */ -#ifdef CONFIG_DEBUG_VM_VMACACHE - "vmacache_find_calls", - "vmacache_find_hits", -#endif #ifdef CONFIG_SWAP "swap_ra", "swap_ra_hit",