Adds ShmOther, ShmOrphan, ShmSwapCache and ShmSwap lines to /proc/<pid>/smaps for shmem mappings.
ShmOther: amount of memory that is currently resident in memory, not present in the page table of this process but present in the page table of an other process. ShmOrphan: amount of memory that is currently resident in memory but not present in any process page table. This can happens when a process unmaps a shared mapping it has accessed before or exits. Despite being resident, this memory is not currently accounted to any process. ShmSwapcache: amount of memory currently in swap cache ShmSwap: amount of memory that is paged out on disk. Signed-off-by: Jerome Marchand <[email protected]> --- Documentation/filesystems/proc.txt | 11 ++++++++ fs/proc/task_mmu.c | 56 +++++++++++++++++++++++++++++++++++++- 2 files changed, 66 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 1a15c56..a65ab59 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -422,6 +422,10 @@ Swap: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 374 kB +ShmOther: 124 kB +ShmOrphan: 0 kB +ShmSwapCache: 12 kB +ShmSwap: 36 kB VmFlags: rd ex mr mw me de the first of these lines shows the same information as is displayed for the @@ -437,6 +441,13 @@ a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE and a page is modified, the file page is replaced by a private anonymous copy. "Swap" shows how much would-be-anonymous memory is also used, but out on swap. +The ShmXXX lines only appears for shmem mapping. They show the amount of memory +from the mapping that is currently: + - resident in RAM, not present in the page table of this process but present + in the page table of an other process (ShmOther) + - resident in RAM but not present in the page table of any process (ShmOrphan) + - in swap cache (ShmSwapCache) + - paged out on swap (ShmSwap). "VmFlags" field deserves a separate description. This member represents the kernel flags associated with the particular virtual memory area in two letter encoded diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 73f0ce4..9b1de55 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -518,9 +518,33 @@ struct mem_size_stats { unsigned long anonymous_thp; unsigned long swap; unsigned long nonlinear; + unsigned long shmem_resident_other; + unsigned long shmem_swapcache; + unsigned long shmem_swap; + unsigned long shmem_orphan; u64 pss; }; +void update_shmem_stats(struct mem_size_stats *mss, struct vm_area_struct *vma, + pgoff_t pgoff, unsigned long size) +{ + int count = 0; + + switch (shmem_locate(vma, pgoff, &count)) { + case SHMEM_RESIDENT: + if (count) + mss->shmem_resident_other += size; + else + mss->shmem_orphan += size; + break; + case SHMEM_SWAPCACHE: + mss->shmem_swapcache += size; + break; + case SHMEM_SWAP: + mss->shmem_swap += size; + break; + } +} static void smaps_pte_entry(pte_t ptent, unsigned long addr, unsigned long ptent_size, struct mm_walk *walk) @@ -543,7 +567,8 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr, } else if (pte_file(ptent)) { if (pte_to_pgoff(ptent) != pgoff) mss->nonlinear += ptent_size; - } + } else if (pte_none(ptent) && shmem_vma(vma)) + update_shmem_stats(mss, vma, pgoff, ptent_size); if (!page) return; @@ -604,6 +629,21 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, return 0; } +static int smaps_pte_hole(unsigned long addr, unsigned long end, + struct mm_walk *walk) +{ + struct mem_size_stats *mss = walk->private; + struct vm_area_struct *vma = mss->vma; + pgoff_t pgoff; + + for (; addr != end; addr += PAGE_SIZE) { + pgoff = linear_page_index(vma, addr); + update_shmem_stats(mss, vma, pgoff, PAGE_SIZE); + } + + return 0; +} + static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) { /* @@ -670,6 +710,10 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) .private = &mss, }; + /* Only walk the holes when it'a a shmem mapping */ + if (shmem_vma(vma)) + smaps_walk.pte_hole = smaps_pte_hole; + memset(&mss, 0, sizeof mss); mss.vma = vma; /* mmap_sem is held in m_start */ @@ -712,6 +756,16 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) if (vma->vm_flags & VM_NONLINEAR) seq_printf(m, "Nonlinear: %8lu kB\n", mss.nonlinear >> 10); + if (shmem_vma(vma)) + seq_printf(m, + "ShmOther: %8lu kB\n" + "ShmOrphan: %8lu kB\n" + "ShmSwapCache: %8lu kB\n" + "ShmSwap: %8lu kB\n", + mss.shmem_resident_other >> 10, + mss.shmem_orphan >> 10, + mss.shmem_swapcache >> 10, + mss.shmem_swap >> 10); show_smap_vma_flags(m, vma); -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
