In many data center servers, the shared memory architectures is Non-Uniform Memory Access (NUMA), remote numa node data access often brings a high latency problem, but what we are easy to ignore is that the page table remote numa access, It can also leads to a performance degradation. So there add a new interface in /proc, This will help developers to get more info about performance issues if they are caused by cross-NUMA. V1 -> V2 1, As Matthew Wilcox advise, Simplify the codes. 2, Do some codes format fix. V1: https://lore.kernel.org/linux-mm/YuVqdcY8Ibib2LJa@xxxxxxxxxxxxxxxxxxxx/T/ Signed-off-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx> --- fs/proc/base.c | 2 ++ fs/proc/internal.h | 1 + fs/proc/task_mmu.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 90 insertions(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index 8dfa36a99c74..487e82dd3275 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3224,6 +3224,7 @@ static const struct pid_entry tgid_base_stuff[] = { REG("maps", S_IRUGO, proc_pid_maps_operations), #ifdef CONFIG_NUMA REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), + REG("numa_pgtable", S_IRUGO, proc_pid_numa_pgtable_operations), #endif REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), LNK("cwd", proc_cwd_link), @@ -3571,6 +3572,7 @@ static const struct pid_entry tid_base_stuff[] = { #endif #ifdef CONFIG_NUMA REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations), + REG("numa_pgtable", S_IRUGO, proc_pid_numa_pgtable_operations), #endif REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations), LNK("cwd", proc_cwd_link), diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 06a80f78433d..e7ed9ef097b6 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -296,6 +296,7 @@ struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode); extern const struct file_operations proc_pid_maps_operations; extern const struct file_operations proc_pid_numa_maps_operations; +extern const struct file_operations proc_pid_numa_pgtable_operations; extern const struct file_operations proc_pid_smaps_operations; extern const struct file_operations proc_pid_smaps_rollup_operations; extern const struct file_operations proc_clear_refs_operations; diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2d04e3470d4c..967e46f523a0 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1999,4 +1999,91 @@ const struct file_operations proc_pid_numa_maps_operations = { .release = proc_map_release, }; +struct pgtable_numa_private { + struct proc_maps_private proc_maps; + unsigned long node[MAX_NUMNODES]; +}; + +static int gather_pgtable_numa_stats(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct pgtable_numa_private *priv = walk->private; + struct page *page; + int nid; + + if (pmd_huge(*pmd)) { + page = virt_to_page(pmd); + } else { + page = pmd_page(*pmd); + } + + nid = page_to_nid(page); + priv->node[nid]++; + + return 0; +} + +static const struct mm_walk_ops show_numa_pgtable_ops = { + .pmd_entry = gather_pgtable_numa_stats, +}; + +/* + * Display the page talbe allocated per node via /proc. + */ +static int show_numa_pgtable(struct seq_file *m, void *v) +{ + struct pgtable_numa_private *numa_priv = m->private; + struct vm_area_struct *vma = v; + struct mm_struct *mm = vma->vm_mm; + struct file *file = vma->vm_file; + int nid; + + if (!mm) + return 0; + + memset(numa_priv->node, 0, MAX_NUMNODES); + + seq_printf(m, "%08lx ", vma->vm_start); + + if (file) { + seq_puts(m, " file="); + seq_file_path(m, file, "\n\t= "); + } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { + seq_puts(m, " heap"); + } else if (is_stack(vma)) { + seq_puts(m, " stack"); + } + + /* mmap_lock is held by m_start */ + walk_page_vma(vma, &show_numa_pgtable_ops, numa_priv); + + for_each_node_state(nid, N_MEMORY) { + if (numa_priv->node[nid]) + seq_printf(m, " N%d=%lu", nid, numa_priv->node[nid]); + } + seq_putc(m, '\n'); + + return 0; +} + +static const struct seq_operations proc_pid_numa_pgtable_op = { + .start = m_start, + .next = m_next, + .stop = m_stop, + .show = show_numa_pgtable, +}; + +static int pid_numa_pgtable_open(struct inode *inode, struct file *file) +{ + return proc_maps_open(inode, file, &proc_pid_numa_pgtable_op, + sizeof(struct pgtable_numa_private)); +} + +const struct file_operations proc_pid_numa_pgtable_operations = { + .open = pid_numa_pgtable_open, + .read = seq_read, + .llseek = seq_lseek, + .release = proc_map_release, +}; + #endif /* CONFIG_NUMA */ -- 2.31.0
