Use the new __seq_open_private_buffer to estimate the final output /proc/<pid>/smaps filesize to reduce the number of reallocations of overflowed buffers.
Use a simpler single-line function to emit various values in kB. Signed-off-by: Joe Perches <[email protected]> --- fs/proc/task_mmu.c | 94 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 48 insertions(+), 46 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 187d84e..170509b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -224,19 +224,21 @@ static void m_stop(struct seq_file *m, void *v) static int proc_maps_open(struct inode *inode, struct file *file, const struct seq_operations *ops, int psize) { - struct proc_maps_private *priv = __seq_open_private(file, ops, psize); + struct proc_maps_private *priv; + struct mm_struct *mm; + + mm = proc_mem_open(inode, PTRACE_MODE_READ); + if (IS_ERR(mm)) + return PTR_ERR(mm); + priv = __seq_open_private_bufsize(file, ops, psize, + mm && mm->map_count ? + mm->map_count * 0x300 : PAGE_SIZE); if (!priv) return -ENOMEM; priv->inode = inode; - priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR(priv->mm)) { - int err = PTR_ERR(priv->mm); - - seq_release_private(inode, file); - return err; - } + priv->mm = mm; return 0; } @@ -721,6 +723,25 @@ void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma) { } +static void show_val_kb(struct seq_file *m, const char *s, unsigned long num) +{ + char v[32]; + static const char blanks[7] = {' ', ' ', ' ', ' ',' ', ' ', ' '}; + int len; + + len = num_to_str(v, sizeof(v), num >> 10); + + seq_write(m, s, 16); + + if (len > 0) { + if (len < 8) + seq_write(m, blanks, 8 - len); + + seq_write(m, v, len); + } + seq_write(m, " kB\n", 4); +} + static int show_smap(struct seq_file *m, void *v, int is_pid) { struct vm_area_struct *vma = v; @@ -765,44 +786,25 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) show_map_vma(m, vma, is_pid); - 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" - "Private_Dirty: %8lu kB\n" - "Referenced: %8lu kB\n" - "Anonymous: %8lu kB\n" - "AnonHugePages: %8lu kB\n" - "ShmemPmdMapped: %8lu kB\n" - "Shared_Hugetlb: %8lu kB\n" - "Private_Hugetlb: %7lu kB\n" - "Swap: %8lu kB\n" - "SwapPss: %8lu kB\n" - "KernelPageSize: %8lu kB\n" - "MMUPageSize: %8lu kB\n" - "Locked: %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, - mss.private_dirty >> 10, - mss.referenced >> 10, - mss.anonymous >> 10, - mss.anonymous_thp >> 10, - mss.shmem_thp >> 10, - mss.shared_hugetlb >> 10, - mss.private_hugetlb >> 10, - mss.swap >> 10, - (unsigned long)(mss.swap_pss >> (10 + PSS_SHIFT)), - vma_kernel_pagesize(vma) >> 10, - vma_mmu_pagesize(vma) >> 10, - (vma->vm_flags & VM_LOCKED) ? - (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); + show_val_kb(m, "Size: ", vma->vm_end - vma->vm_start); + show_val_kb(m, "Rss: ", mss.resident); + show_val_kb(m, "Pss: ", mss.pss >> PSS_SHIFT); + show_val_kb(m, "Shared_Clean: ", mss.shared_clean); + show_val_kb(m, "Shared_Dirty: ", mss.shared_dirty); + show_val_kb(m, "Private_Clean: ", mss.private_clean); + show_val_kb(m, "Private_Dirty: ", mss.private_dirty); + show_val_kb(m, "Referenced: ", mss.referenced); + show_val_kb(m, "Anonymous: ", mss.anonymous); + show_val_kb(m, "AnonHugePages: ", mss.anonymous_thp); + show_val_kb(m, "ShmemPmdMapped: ", mss.shmem_thp); + show_val_kb(m, "Shared_Hugetlb: ", mss.shared_hugetlb); + seq_printf(m, "Private_Hugetlb: %7lu kB\n", mss.private_hugetlb >> 10); + show_val_kb(m, "Swap: ", mss.swap); + show_val_kb(m, "SwapPss: ", mss.swap_pss >> PSS_SHIFT); + show_val_kb(m, "KernelPageSize: ", vma_kernel_pagesize(vma)); + show_val_kb(m, "MMUPageSize: ", vma_mmu_pagesize(vma)); + show_val_kb(m, "Locked: ", + vma->vm_flags & VM_LOCKED ? mss.pss >> PSS_SHIFT : 0); arch_show_smap(m, vma); show_smap_vma_flags(m, vma); -- 2.8.0.rc4.16.g56331f8
