| Message ID | 20220801032704.64356-1-xhao@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,V3] mm: add last level page table numa info to /proc/pid/numa_pgtable | expand |
Hi Xin, On 8/1/2022 11:27 AM, Xin Hao wrote: > 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. > > V2 -> V3 > 1, Fix compile warning bug. > > V1 -> V2 > 1, As Matthew Wilcox advise, Simplify the code. > 2, Do some codes format fix. Please move the changes history under your 'Signed-off-by' with '---'. > > V2: https://lore.kernel.org/linux-mm/20220731155223.60238-1-xhao@linux.alibaba.com/ > V1: https://lore.kernel.org/linux-mm/YuVqdcY8Ibib2LJa@casper.infradead.org/T/ > > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Xin Hao <xhao@linux.alibaba.com> > --- > 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..77b7a49757f5 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); You should validate if the pmd is valid or present before getting the pagetable page. if (pmd_none(*pmd) || !pmd_present(*pmd)) Another issue is I think you should hold the pmd lock to call pmd_page(), since after the validation of pmd_huge(), the pmd entry can be modified by other threads if you did not hold the pmd lock. > + } > + > + 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, sizeof(numa_priv->node)); > + > + 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
在 2022/8/1 下午2:06, Baolin Wang 写道: > Hi Xin, > > On 8/1/2022 11:27 AM, Xin Hao wrote: >> 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. >> >> V2 -> V3 >> 1, Fix compile warning bug. >> >> V1 -> V2 >> 1, As Matthew Wilcox advise, Simplify the code. >> 2, Do some codes format fix. > > Please move the changes history under your 'Signed-off-by' with '---'. > >> >> V2: >> https://lore.kernel.org/linux-mm/20220731155223.60238-1-xhao@linux.alibaba.com/ >> V1: >> https://lore.kernel.org/linux-mm/YuVqdcY8Ibib2LJa@casper.infradead.org/T/ >> >> Reported-by: kernel test robot <lkp@intel.com> >> Signed-off-by: Xin Hao <xhao@linux.alibaba.com> >> --- >> 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..77b7a49757f5 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); > > You should validate if the pmd is valid or present before getting the > pagetable page. > > if (pmd_none(*pmd) || !pmd_present(*pmd)) > > Another issue is I think you should hold the pmd lock to call > pmd_page(), since after the validation of pmd_huge(), the pmd entry > can be modified by other threads if you did not hold the pmd lock. > Thanks, Baolin, i will fix it in the next version. >> + } >> + >> + 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, sizeof(numa_priv->node)); >> + >> + 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
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..77b7a49757f5 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, sizeof(numa_priv->node)); + + 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 */
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. V2 -> V3 1, Fix compile warning bug. V1 -> V2 1, As Matthew Wilcox advise, Simplify the code. 2, Do some codes format fix. V2: https://lore.kernel.org/linux-mm/20220731155223.60238-1-xhao@linux.alibaba.com/ V1: https://lore.kernel.org/linux-mm/YuVqdcY8Ibib2LJa@casper.infradead.org/T/ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Xin Hao <xhao@linux.alibaba.com> --- fs/proc/base.c | 2 ++ fs/proc/internal.h | 1 + fs/proc/task_mmu.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 90 insertions(+) -- 2.31.0