diff options
| -rw-r--r-- | fs/proc/task_mmu.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 8043a3eab52c..8952ce70315e 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -114,6 +114,25 @@ static void pad_len_spaces(struct seq_file *m, int len) seq_printf(m, "%*c", len, ' '); } +/* + * Proportional Set Size(PSS): my share of RSS. + * + * PSS of a process is the count of pages it has in memory, where each + * page is divided by the number of processes sharing it. So if a + * process has 1000 pages all to itself, and 1000 shared with one other + * process, its PSS will be 1500. + * + * To keep (accumulated) division errors low, we adopt a 64bit + * fixed-point pss counter to minimize division errors. So (pss >> + * PSS_SHIFT) would be the real byte count. + * + * A shift of 12 before division means (assuming 4K page size): + * - 1M 3-user-pages add up to 8KB errors; + * - supports mapcount up to 2^24, or 16M; + * - supports PSS up to 2^52 bytes, or 4PB. + */ +#define PSS_SHIFT 12 + struct mem_size_stats { unsigned long resident; @@ -122,6 +141,7 @@ struct mem_size_stats unsigned long private_clean; unsigned long private_dirty; unsigned long referenced; + u64 pss; }; struct pmd_walker { @@ -195,6 +215,7 @@ static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats seq_printf(m, "Size: %8lu kB\n" "Rss: %8lu kB\n" + "Pss: %8lu kB\n" "Shared_Clean: %8lu kB\n" "Shared_Dirty: %8lu kB\n" "Private_Clean: %8lu kB\n" @@ -202,6 +223,7 @@ static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats "Referenced: %8lu kB\n", (vma->vm_end - vma->vm_start) >> 10, mss->resident >> 10, + (unsigned long)(mss->pss >> (10 + PSS_SHIFT)), mss->shared_clean >> 10, mss->shared_dirty >> 10, mss->private_clean >> 10, @@ -226,6 +248,7 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd, pte_t *pte, ptent; spinlock_t *ptl; struct page *page; + int mapcount; pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) { @@ -242,16 +265,19 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd, /* Accumulate the size in pages that have been accessed. */ if (pte_young(ptent) || PageReferenced(page)) mss->referenced += PAGE_SIZE; - if (page_mapcount(page) >= 2) { + mapcount = page_mapcount(page); + if (mapcount >= 2) { if (pte_dirty(ptent)) mss->shared_dirty += PAGE_SIZE; else mss->shared_clean += PAGE_SIZE; + mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount; } else { if (pte_dirty(ptent)) mss->private_dirty += PAGE_SIZE; else mss->private_clean += PAGE_SIZE; + mss->pss += (PAGE_SIZE << PSS_SHIFT); } } pte_unmap_unlock(pte - 1, ptl); |