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proc: add seq_put_decimal_ull_width to speed up /proc/pid/smaps 

seq_put_decimal_ull_w(m, str, val, width) prints a decimal number with a
specified minimal field width.

It is equivalent of seq_printf(m, "%s%*d", str, width, val), but it
works much faster.

== test_smaps.py
  num = 0
  with open("/proc/1/smaps") as f:
          for x in xrange(10000):
                  data = f.read()
                  f.seek(0, 0)
==

== Before patch ==
  $ time python test_smaps.py
  real    0m4.593s
  user    0m0.398s
  sys     0m4.158s

== After patch ==
  $ time python test_smaps.py
  real    0m3.828s
  user    0m0.413s
  sys     0m3.408s

$ perf -g record python test_smaps.py
== Before patch ==
-   79.01%     3.36%  python   [kernel.kallsyms]    [k] show_smap.isra.33
   - 75.65% show_smap.isra.33
      + 48.85% seq_printf
      + 15.75% __walk_page_range
      + 9.70% show_map_vma.isra.23
        0.61% seq_puts

== After patch ==
-   75.51%     4.62%  python   [kernel.kallsyms]    [k] show_smap.isra.33
   - 70.88% show_smap.isra.33
      + 24.82% seq_put_decimal_ull_w
      + 19.78% __walk_page_range
      + 12.74% seq_printf
      + 11.08% show_map_vma.isra.23
      + 1.68% seq_puts

[akpm@linux-foundation.org: fix drivers/of/unittest.c build]
Link: http://lkml.kernel.org/r/20180212074931.7227-1-avagin@openvz.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Andrei Vagin 2018-04-10 16:31:16 -07:00 committed by Linus Torvalds
parent 2acddbe816
commit d1be35cb6f
7 changed files with 93 additions and 102 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/of/unittest.c
View File

@ -295,7 +295,7 @@ static void __init of_unittest_printf(void)
return;
}
num_to_str(phandle_str, sizeof(phandle_str), np->phandle);
num_to_str(phandle_str, sizeof(phandle_str), np->phandle, 0);
of_unittest_printf_one(np, "%pOF", full_name);
of_unittest_printf_one(np, "%pOFf", full_name);

15
fs/proc/meminfo.c
View File

@ -26,20 +26,7 @@ void __attribute__((weak)) arch_report_meminfo(struct seq_file *m)
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 << (PAGE_SHIFT - 10));
seq_write(m, s, 16);
if (len > 0) {
if (len < 8)
seq_write(m, blanks, 8 - len);
seq_write(m, v, len);
}
seq_put_decimal_ull_width(m, s, num << (PAGE_SHIFT - 10), 8);
seq_write(m, " kB\n", 4);
}

127
fs/proc/task_mmu.c
View File

@ -24,6 +24,8 @@
#include <asm/tlbflush.h>
#include "internal.h"
#define SEQ_PUT_DEC(str, val) \
seq_put_decimal_ull_width(m, str, (val) << (PAGE_SHIFT-10), 8)
void task_mem(struct seq_file *m, struct mm_struct *mm)
{
unsigned long text, lib, swap, anon, file, shmem;
@ -53,39 +55,28 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
lib = (mm->exec_vm << PAGE_SHIFT) - text;
swap = get_mm_counter(mm, MM_SWAPENTS);
seq_printf(m,
"VmPeak:\t%8lu kB\n"
"VmSize:\t%8lu kB\n"
"VmLck:\t%8lu kB\n"
"VmPin:\t%8lu kB\n"
"VmHWM:\t%8lu kB\n"
"VmRSS:\t%8lu kB\n"
"RssAnon:\t%8lu kB\n"
"RssFile:\t%8lu kB\n"
"RssShmem:\t%8lu kB\n"
"VmData:\t%8lu kB\n"
"VmStk:\t%8lu kB\n"
"VmExe:\t%8lu kB\n"
"VmLib:\t%8lu kB\n"
"VmPTE:\t%8lu kB\n"
"VmSwap:\t%8lu kB\n",
hiwater_vm << (PAGE_SHIFT-10),
total_vm << (PAGE_SHIFT-10),
mm->locked_vm << (PAGE_SHIFT-10),
mm->pinned_vm << (PAGE_SHIFT-10),
hiwater_rss << (PAGE_SHIFT-10),
total_rss << (PAGE_SHIFT-10),
anon << (PAGE_SHIFT-10),
file << (PAGE_SHIFT-10),
shmem << (PAGE_SHIFT-10),
mm->data_vm << (PAGE_SHIFT-10),
mm->stack_vm << (PAGE_SHIFT-10),
text >> 10,
lib >> 10,
mm_pgtables_bytes(mm) >> 10,
swap << (PAGE_SHIFT-10));
SEQ_PUT_DEC("VmPeak:\t", hiwater_vm);
SEQ_PUT_DEC(" kB\nVmSize:\t", total_vm);
SEQ_PUT_DEC(" kB\nVmLck:\t", mm->locked_vm);
SEQ_PUT_DEC(" kB\nVmPin:\t", mm->pinned_vm);
SEQ_PUT_DEC(" kB\nVmHWM:\t", hiwater_rss);
SEQ_PUT_DEC(" kB\nVmRSS:\t", total_rss);
SEQ_PUT_DEC(" kB\nRssAnon:\t", anon);
SEQ_PUT_DEC(" kB\nRssFile:\t", file);
SEQ_PUT_DEC(" kB\nRssShmem:\t", shmem);
SEQ_PUT_DEC(" kB\nVmData:\t", mm->data_vm);
SEQ_PUT_DEC(" kB\nVmStk:\t", mm->stack_vm);
seq_put_decimal_ull_width(m,
" kB\nVmExe:\t", text >> 10, 8);
seq_put_decimal_ull_width(m,
" kB\nVmLib:\t", lib >> 10, 8);
seq_put_decimal_ull_width(m,
" kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8);
SEQ_PUT_DEC(" kB\nVmSwap:\t", swap);
seq_puts(m, " kB\n");
hugetlb_report_usage(m, mm);
}
#undef SEQ_PUT_DEC
unsigned long task_vsize(struct mm_struct *mm)
{
@ -739,6 +730,8 @@ void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
{
}
#define SEQ_PUT_DEC(str, val) \
seq_put_decimal_ull_width(m, str, (val) >> 10, 8)
static int show_smap(struct seq_file *m, void *v, int is_pid)
{
struct proc_maps_private *priv = m->private;
@ -812,51 +805,34 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
ret = SEQ_SKIP;
}
if (!rollup_mode)
seq_printf(m,
"Size: %8lu kB\n"
"KernelPageSize: %8lu kB\n"
"MMUPageSize: %8lu kB\n",
(vma->vm_end - vma->vm_start) >> 10,
vma_kernel_pagesize(vma) >> 10,
vma_mmu_pagesize(vma) >> 10);
if (!rollup_mode || last_vma)
seq_printf(m,
"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"
"LazyFree: %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"
"Locked: %8lu kB\n",
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->lazyfree >> 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)),
(unsigned long)(mss->pss >> (10 + PSS_SHIFT)));
if (!rollup_mode) {
SEQ_PUT_DEC("Size: ", vma->vm_end - vma->vm_start);
SEQ_PUT_DEC(" kB\nKernelPageSize: ", vma_kernel_pagesize(vma));
SEQ_PUT_DEC(" kB\nMMUPageSize: ", vma_mmu_pagesize(vma));
seq_puts(m, " kB\n");
}
if (!rollup_mode || last_vma) {
SEQ_PUT_DEC("Rss: ", mss->resident);
SEQ_PUT_DEC(" kB\nPss: ", mss->pss >> PSS_SHIFT);
SEQ_PUT_DEC(" kB\nShared_Clean: ", mss->shared_clean);
SEQ_PUT_DEC(" kB\nShared_Dirty: ", mss->shared_dirty);
SEQ_PUT_DEC(" kB\nPrivate_Clean: ", mss->private_clean);
SEQ_PUT_DEC(" kB\nPrivate_Dirty: ", mss->private_dirty);
SEQ_PUT_DEC(" kB\nReferenced: ", mss->referenced);
SEQ_PUT_DEC(" kB\nAnonymous: ", mss->anonymous);
SEQ_PUT_DEC(" kB\nLazyFree: ", mss->lazyfree);
SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp);
SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
mss->private_hugetlb >> 10, 7);
SEQ_PUT_DEC(" kB\nSwap: ", mss->swap);
SEQ_PUT_DEC(" kB\nSwapPss: ",
mss->swap_pss >> PSS_SHIFT);
SEQ_PUT_DEC(" kB\nLocked: ", mss->pss >> PSS_SHIFT);
seq_puts(m, " kB\n");
}
if (!rollup_mode) {
arch_show_smap(m, vma);
show_smap_vma_flags(m, vma);
@ -864,6 +840,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
m_cache_vma(m, vma);
return ret;
}
#undef SEQ_PUT_DEC
static int show_pid_smap(struct seq_file *m, void *v)
{

28
fs/seq_file.c
View File

@ -673,15 +673,20 @@ void seq_puts(struct seq_file *m, const char *s)
}
EXPORT_SYMBOL(seq_puts);
/*
/**
* A helper routine for putting decimal numbers without rich format of printf().
* only 'unsigned long long' is supported.
* This routine will put strlen(delimiter) + number into seq_file.
* @m: seq_file identifying the buffer to which data should be written
* @delimiter: a string which is printed before the number
* @num: the number
* @width: a minimum field width
*
* This routine will put strlen(delimiter) + number into seq_filed.
* This routine is very quick when you show lots of numbers.
* In usual cases, it will be better to use seq_printf(). It's easier to read.
*/
void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
unsigned long long num)
void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
unsigned long long num, unsigned int width)
{
int len;
@ -695,7 +700,10 @@ void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
memcpy(m->buf + m->count, delimiter, len);
m->count += len;
if (m->count + 1 >= m->size)
if (!width)
width = 1;
if (m->count + width >= m->size)
goto overflow;
if (num < 10) {
@ -703,7 +711,7 @@ void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
return;
}
len = num_to_str(m->buf + m->count, m->size - m->count, num);
len = num_to_str(m->buf + m->count, m->size - m->count, num, width);
if (!len)
goto overflow;
@ -713,6 +721,12 @@ void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
overflow:
seq_set_overflow(m);
}
void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
unsigned long long num)
{
return seq_put_decimal_ull_width(m, delimiter, num, 0);
}
EXPORT_SYMBOL(seq_put_decimal_ull);
/**
@ -788,7 +802,7 @@ void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num
return;
}
len = num_to_str(m->buf + m->count, m->size - m->count, num);
len = num_to_str(m->buf + m->count, m->size - m->count, num, 0);
if (!len)
goto overflow;

3
include/linux/kernel.h
View File

@ -439,7 +439,8 @@ extern long simple_strtol(const char *,char **,unsigned int);
extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
extern long long simple_strtoll(const char *,char **,unsigned int);
extern int num_to_str(char *buf, int size, unsigned long long num);
extern int num_to_str(char *buf, int size,
unsigned long long num, unsigned int width);
/* lib/printf utilities */

2
include/linux/seq_file.h
View File

@ -118,6 +118,8 @@ __printf(2, 3)
void seq_printf(struct seq_file *m, const char *fmt, ...);
void seq_putc(struct seq_file *m, char c);
void seq_puts(struct seq_file *m, const char *s);
void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
unsigned long long num, unsigned int width);
void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
unsigned long long num);
void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num);

18
lib/vsprintf.c
View File

@ -336,7 +336,7 @@ char *put_dec(char *buf, unsigned long long n)
*
* If speed is not important, use snprintf(). It's easy to read the code.
*/
int num_to_str(char *buf, int size, unsigned long long num)
int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
{
/* put_dec requires 2-byte alignment of the buffer. */
char tmp[sizeof(num) * 3] __aligned(2);
@ -350,11 +350,21 @@ int num_to_str(char *buf, int size, unsigned long long num)
len = put_dec(tmp, num) - tmp;
}
if (len > size)
if (len > size || width > size)
return 0;
if (width > len) {
width = width - len;
for (idx = 0; idx < width; idx++)
buf[idx] = ' ';
} else {
width = 0;
}
for (idx = 0; idx < len; ++idx)
buf[idx] = tmp[len - idx - 1];
return len;
buf[idx + width] = tmp[len - idx - 1];
return len + width;
}
#define SIGN 1 /* unsigned/signed, must be 1 */