ascend inclusion category: Feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8LNGH
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Alloc share memory for tasks in a share pool group. The tasks in the same pool could access the memory with the same virtual address.
When the user calling mg_sp_alloc(), the physical memory is allocated in do_mm_populate() for the first process and the pages are charged into the memcg of that process. We should start at the current process so as to charge the pages to the memcg of current process.
Signed-off-by: Wang Wensheng wangwensheng4@huawei.com --- mm/share_pool.c | 359 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 357 insertions(+), 2 deletions(-)
diff --git a/mm/share_pool.c b/mm/share_pool.c index 5adf9ddaef20..d677bd3f361c 100644 --- a/mm/share_pool.c +++ b/mm/share_pool.c @@ -482,6 +482,11 @@ static inline bool is_local_group(int spg_id) return spg_id >= SPG_ID_LOCAL_MIN && spg_id <= SPG_ID_LOCAL_MAX; }
+static int sp_init_group_master(struct task_struct *tsk, struct mm_struct *mm) +{ + return -EOPNOTSUPP; +} + static void update_mem_usage_alloc(unsigned long size, bool inc, bool is_hugepage, struct sp_group_node *spg_node) { @@ -692,6 +697,16 @@ static inline void check_interrupt_context(void) panic("function can't be used in interrupt context\n"); }
+struct sp_alloc_context { + unsigned long size; + unsigned long size_aligned; + unsigned long sp_flags; + nodemask_t *nodemask; + int preferred_node_id; + bool have_mbind; + enum spa_type type; +}; + /* * Get the sp_group from the mm and return the associated sp_group_node. * The caller should promise the @mm would not be deleted from the @spg. @@ -751,6 +766,11 @@ int mg_sp_group_id_by_pid(int tgid, int *spg_ids, int *num) } EXPORT_SYMBOL_GPL(mg_sp_group_id_by_pid);
+static bool is_online_node_id(int node_id) +{ + return node_id >= 0 && node_id < MAX_NUMNODES && node_online(node_id); +} + /** * mg_sp_group_add_task() - Add a process to an share group (sp_group). * @tgid: the tgid of the task to be added. @@ -1258,10 +1278,345 @@ static void __init proc_sharepool_init(void) return; }
+/* wrapper of __do_mmap() and the caller must hold mmap_write_lock(mm). */ +static unsigned long sp_mmap(struct mm_struct *mm, struct file *file, + struct sp_area *spa, unsigned long *populate, + unsigned long prot) +{ + unsigned long addr = spa->va_start; + unsigned long size = spa_size(spa); + unsigned long flags = MAP_FIXED_NOREPLACE | MAP_SHARED | MAP_POPULATE | + MAP_SHARE_POOL; + unsigned long vm_flags = VM_NORESERVE | VM_SHARE_POOL | VM_DONTCOPY; + unsigned long pgoff = addr_offset(spa) >> PAGE_SHIFT; + struct vm_area_struct *vma; + + if (spa->flags & SP_PROT_RO) + prot &= ~PROT_WRITE; + + atomic_inc(&spa->use_count); + addr = __do_mmap_mm(mm, file, addr, size, prot, flags, vm_flags, pgoff, + populate, NULL); + if (IS_ERR_VALUE(addr)) { + atomic_dec(&spa->use_count); + pr_err("do_mmap fails %ld\n", addr); + return addr; + } + + vma = find_vma(mm, addr); + vma->spa = spa; + + if (prot & PROT_WRITE) + /* clean PTE_RDONLY flags or trigger SMMU event */ + vma->vm_page_prot = __pgprot(((~PTE_RDONLY) & vma->vm_page_prot.pgprot) | + PTE_DIRTY); + else + vm_flags_clear(vma, VM_MAYWRITE); + + return addr; +} + +static int sp_alloc_prepare(unsigned long size, unsigned long sp_flags, + int spg_id, struct sp_alloc_context *ac) +{ + int device_id, node_id; + + if (!sp_is_enabled()) + return -EOPNOTSUPP; + + check_interrupt_context(); + + device_id = sp_flags_device_id(sp_flags); + node_id = sp_flags & SP_SPEC_NODE_ID ? sp_flags_node_id(sp_flags) : device_id; + if (!is_online_node_id(node_id)) { + pr_err_ratelimited("invalid numa node id %d\n", node_id); + return -EINVAL; + } + ac->preferred_node_id = node_id; + + if (current->flags & PF_KTHREAD) { + pr_err_ratelimited("allocation failed, task is kthread\n"); + return -EINVAL; + } + + if (unlikely(!size || (size >> PAGE_SHIFT) > totalram_pages())) { + pr_err_ratelimited("allocation failed, invalid size %lu\n", size); + return -EINVAL; + } + + if (spg_id != SPG_ID_DEFAULT && (spg_id < SPG_ID_MIN || spg_id >= SPG_ID_AUTO)) { + pr_err_ratelimited("allocation failed, invalid group id %d\n", spg_id); + return -EINVAL; + } + + if (sp_flags & (~SP_FLAG_MASK)) { + pr_err_ratelimited("allocation failed, invalid flag %lx\n", sp_flags); + return -EINVAL; + } + + if (sp_flags & SP_HUGEPAGE_ONLY) + sp_flags |= SP_HUGEPAGE; + + if (spg_id == SPG_ID_DEFAULT) { + /* + * We should first init the group_master in pass through scene and + * don't free it until we release the mm_struct. + */ + int ret = sp_init_group_master(current, current->mm); + + if (ret) { + pr_err("sp_alloc init local mapping failed %d\n", ret); + return ret; + } + } + + ac->type = SPA_TYPE_ALLOC; + ac->size = size; + ac->sp_flags = sp_flags; + ac->have_mbind = false; + ac->size_aligned = (sp_flags & SP_HUGEPAGE) ? ALIGN(size, PMD_SIZE) : + ALIGN(size, PAGE_SIZE); + + return 0; +} + +static bool sp_alloc_fallback(struct sp_area *spa, struct sp_alloc_context *ac) +{ + /* + * If hugepage allocation fails, this will transfer to normal page + * and try again. (only if SP_HUGEPAGE_ONLY is not flagged + */ + if (!(ac->sp_flags & SP_HUGEPAGE) || (ac->sp_flags & SP_HUGEPAGE_ONLY)) + return false; + + ac->size_aligned = ALIGN(ac->size, PAGE_SIZE); + ac->sp_flags &= ~SP_HUGEPAGE; + /* + * The mempolicy for shared memory is located at backend file, which varies + * between normal pages and huge pages. So we should set the mbind policy again + * when we retry using normal pages. + */ + ac->have_mbind = false; + sp_area_put_locked(spa); + return true; +} + +static long sp_mbind(struct mm_struct *mm, unsigned long start, unsigned long len, + nodemask_t *nodemask) +{ + return __do_mbind(start, len, MPOL_BIND, MPOL_F_STATIC_NODES, + nodemask, MPOL_MF_STRICT, mm); +} + +static int sp_alloc_populate(struct mm_struct *mm, struct sp_area *spa, + unsigned long populate, struct sp_alloc_context *ac) +{ + int ret; + + if (ac && !ac->have_mbind) { + ret = sp_mbind(mm, spa->va_start, spa->real_size, ac->nodemask); + if (ret < 0) { + pr_err("cannot bind the memory range to node[%*pbl], err:%d\n", + nodemask_pr_args(ac->nodemask), ret); + return ret; + } + ac->have_mbind = true; + } + + /* + * We are not ignoring errors, so if we fail to allocate + * physical memory we just return failure, so we won't encounter + * page fault later on, and more importantly sp_make_share_u2k() + * depends on this feature (and MAP_LOCKED) to work correctly. + */ + ret = do_mm_populate(mm, spa->va_start, populate, 0); + if (ac && (ac->sp_flags & SP_HUGEPAGE) && unlikely(ret == -EFAULT)) + ret = -ENOMEM; + if (ret) { + if (unlikely(fatal_signal_pending(current))) + pr_warn("allocation failed, current thread is killed\n"); + else + pr_warn("allocation failed due to mm populate failed(potential no enough memory when -12): %d\n", + ret); + } + + return ret; +} + +static int sp_k2u_populate(struct mm_struct *mm, struct sp_area *spa) +{ + return -EOPNOTSUPP; +} + +#define SP_SKIP_ERR 1 +/* + * The caller should increase the refcnt of the spa to prevent that we map + * a dead spa into a mm_struct. + */ +static int sp_map_spa_to_mm(struct mm_struct *mm, struct sp_area *spa, + unsigned long prot, struct sp_alloc_context *ac, + const char *str) +{ + int ret; + unsigned long mmap_addr; + unsigned long populate = 0; + + mmap_write_lock(mm); + if (unlikely(!mmget_not_zero(mm))) { + mmap_write_unlock(mm); + pr_warn("sp_map: target mm is exiting\n"); + return SP_SKIP_ERR; + } + + /* when success, mmap_addr == spa->va_start */ + mmap_addr = sp_mmap(mm, spa_file(spa), spa, &populate, prot); + if (IS_ERR_VALUE(mmap_addr)) { + mmap_write_unlock(mm); + mmput_async(mm); + pr_err("%s, sp mmap failed %ld\n", str, mmap_addr); + return (int)mmap_addr; + } + + if (spa->type == SPA_TYPE_ALLOC) { + mmap_write_unlock(mm); + ret = sp_alloc_populate(mm, spa, populate, ac); + if (ret) { + mmap_write_lock(mm); + do_munmap(mm, mmap_addr, spa_size(spa), NULL); + mmap_write_unlock(mm); + } + } else { + ret = sp_k2u_populate(mm, spa); + if (ret) { + do_munmap(mm, mmap_addr, spa_size(spa), NULL); + pr_info("k2u populate failed, %d\n", ret); + } + mmap_write_unlock(mm); + } + mmput_async(mm); + + return ret; +} + +static int sp_alloc_mmap_populate(struct sp_area *spa, struct sp_alloc_context *ac, + struct sp_group_node *spg_node) +{ + int ret = 0; + int mmap_ret = 0; + struct mm_struct *mm; + bool reach_current = false; + + mmap_ret = sp_map_spa_to_mm(current->mm, spa, spg_node->prot, ac, "sp_alloc"); + if (mmap_ret) { + /* Don't skip error for current process */ + mmap_ret = (mmap_ret == SP_SKIP_ERR) ? -EINVAL : mmap_ret; + goto fallocate; + } + + /* create mapping for each process in the group */ + list_for_each_entry(spg_node, &spa->spg->proc_head, proc_node) { + mm = spg_node->master->mm; + if (mm == current->mm) { + reach_current = true; + continue; + } + mmap_ret = sp_map_spa_to_mm(mm, spa, spg_node->prot, ac, "sp_alloc"); + if (mmap_ret) { + /* + * Goto fallback procedure upon ERR_VALUE, + * but skip the coredump situation, + * because we don't want one misbehaving process to affect others. + */ + if (mmap_ret != SP_SKIP_ERR) + goto unmap; + + continue; + } + ret = mmap_ret; + } + + return ret; + +unmap: + __sp_free(spa, mm); + if (!reach_current) + sp_munmap(current->mm, spa->va_start, spa_size(spa)); +fallocate: + /* + * Sometimes do_mm_populate() allocates some memory and then failed to + * allocate more. (e.g. memory use reaches cgroup limit.) + * In this case, it will return enomem, but will not free the + * memory which has already been allocated. + * + * So if sp_map_spa_to_mm fails, always call sp_fallocate() + * to make sure backup physical memory of the shared file is freed. + */ + sp_fallocate(spa); + + return mmap_ret; +} + +void *__mg_sp_alloc_nodemask(unsigned long size, unsigned long sp_flags, int spg_id, + nodemask_t *nodemask) +{ + int ret = 0; + struct sp_area *spa; + struct sp_group *spg; + nodemask_t __nodemask; + struct sp_alloc_context ac; + struct sp_group_node *spg_node; + + ret = sp_alloc_prepare(size, sp_flags, spg_id, &ac); + if (ret) + return ERR_PTR(ret); + + if (!nodemask) { /* mg_sp_alloc */ + nodes_clear(__nodemask); + node_set(ac.preferred_node_id, __nodemask); + ac.nodemask = &__nodemask; + } else /* mg_sp_alloc_nodemask */ + ac.nodemask = nodemask; + + spg = sp_group_get_from_mm(current->mm, spg_id, &spg_node); + if (!spg) { + pr_err("allocation failed, can't find group(%d)\n", spg_id); + return ERR_PTR(-ENODEV); + } + + down_write(&spg->rw_lock); +try_again: + spa = sp_area_alloc(ac.size_aligned, ac.sp_flags, spg, + ac.type, current->tgid, ac.preferred_node_id); + if (IS_ERR(spa)) { + up_write(&spg->rw_lock); + pr_err("alloc spa failed in allocation(potential no enough virtual memory when -75): %ld\n", + PTR_ERR(spa)); + ret = PTR_ERR(spa); + goto out; + } + + ret = sp_alloc_mmap_populate(spa, &ac, spg_node); + if (ret == -ENOMEM && sp_alloc_fallback(spa, &ac)) + goto try_again; + + if (!ret) + update_mem_usage(spa_size(spa), true, spa->is_hugepage, spg_node, spa->type); + + sp_area_put_locked(spa); + up_write(&spg->rw_lock); + +out: + sp_group_put(spg); + if (ret) + return ERR_PTR(ret); + else + return (void *)(spa->va_start); +} + void *mg_sp_alloc_nodemask(unsigned long size, unsigned long sp_flags, int spg_id, nodemask_t nodemask) { - return ERR_PTR(-EOPNOTSUPP); + return __mg_sp_alloc_nodemask(size, sp_flags, spg_id, &nodemask); } EXPORT_SYMBOL_GPL(mg_sp_alloc_nodemask);
@@ -1279,7 +1634,7 @@ EXPORT_SYMBOL_GPL(mg_sp_alloc_nodemask); */ void *mg_sp_alloc(unsigned long size, unsigned long sp_flags, int spg_id) { - return ERR_PTR(-EOPNOTSUPP); + return __mg_sp_alloc_nodemask(size, sp_flags, spg_id, NULL); } EXPORT_SYMBOL_GPL(mg_sp_alloc);