| Message ID | 202212300916292181912@zte.com.cn (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ksm: support tracking KSM-placed zero-pages | expand |
On 30.12.22 02:16, yang.yang29@zte.com.cn wrote: > From: xu xin <xu.xin16@zte.com.cn> > > As the number of ksm zero pages is not included in ksm_merging_pages per > process when enabling use_zero_pages, it's unclear of how many actual > pages are merged by KSM. To let users accurately estimate their memory > demands when unsharing KSM zero-pages, it's necessary to show KSM zero- > pages per process. > > since unsharing zero pages placed by KSM accurately is achieved, then > tracking empty pages merging and unmerging is not a difficult thing any > longer. > > Since we already have /proc/<pid>/ksm_stat, just add the information of > zero_pages_sharing in it. > > Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn> > Cc: Xiaokai Ran <ran.xiaokai@zte.com.cn> > Cc: Yang Yang <yang.yang29@zte.com.cn> > Signed-off-by: xu xin <xu.xin16@zte.com.cn> > --- > fs/proc/base.c | 1 + > include/linux/mm_types.h | 7 ++++++- > mm/ksm.c | 2 ++ > 3 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 9e479d7d202b..ac9ebe972be0 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -3207,6 +3207,7 @@ static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns, > mm = get_task_mm(task); > if (mm) { > seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items); > + seq_printf(m, "zero_pages_sharing %lu\n", mm->ksm_zero_pages_sharing); > mmput(mm); > } > > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 4e1031626403..5c734ebc1890 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -776,7 +776,7 @@ struct mm_struct { > #ifdef CONFIG_KSM > /* > * Represent how many pages of this process are involved in KSM > - * merging. > + * merging (not including ksm_zero_pages_sharing). > */ > unsigned long ksm_merging_pages; > /* > @@ -784,6 +784,11 @@ struct mm_struct { > * including merged and not merged. > */ > unsigned long ksm_rmap_items; > + /* > + * Represent how many empty pages are merged with kernel zero > + * pages when enabling KSM use_zero_pages. > + */ > + unsigned long ksm_zero_pages_sharing; Same comment as for previous patch: this counts rmap itmaps, no? ksm_zero_rmap_items might be more appropriate.
diff --git a/fs/proc/base.c b/fs/proc/base.c index 9e479d7d202b..ac9ebe972be0 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3207,6 +3207,7 @@ static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns, mm = get_task_mm(task); if (mm) { seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items); + seq_printf(m, "zero_pages_sharing %lu\n", mm->ksm_zero_pages_sharing); mmput(mm); } diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 4e1031626403..5c734ebc1890 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -776,7 +776,7 @@ struct mm_struct { #ifdef CONFIG_KSM /* * Represent how many pages of this process are involved in KSM - * merging. + * merging (not including ksm_zero_pages_sharing). */ unsigned long ksm_merging_pages; /* @@ -784,6 +784,11 @@ struct mm_struct { * including merged and not merged. */ unsigned long ksm_rmap_items; + /* + * Represent how many empty pages are merged with kernel zero + * pages when enabling KSM use_zero_pages. + */ + unsigned long ksm_zero_pages_sharing; #endif #ifdef CONFIG_LRU_GEN struct { diff --git a/mm/ksm.c b/mm/ksm.c index 72c0722be280..083f5d125373 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -794,6 +794,7 @@ static inline void clean_rmap_item_zero_flag(struct ksm_rmap_item *rmap_item) { if (rmap_item->address & ZERO_PAGE_FLAG) { ksm_zero_pages_sharing--; + rmap_item->mm->ksm_zero_pages_sharing--; rmap_item->address &= PAGE_MASK; } } @@ -2117,6 +2118,7 @@ static int try_to_merge_with_kernel_zero_page(struct ksm_rmap_item *rmap_item, if (!err) { rmap_item->address |= ZERO_PAGE_FLAG; ksm_zero_pages_sharing++; + rmap_item->mm->ksm_zero_pages_sharing++; } } else { /* If the vma is out of date, we do not need to continue. */