Commit d1be35cb authored by Andrei Vagin's avatar Andrei Vagin Committed by Linus Torvalds
Browse files

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: default avatarAndrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2acddbe8

drivers/of/unittest.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

fs/proc/meminfo.c

+1 −14
Original line number Diff line number Diff line
@@ -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);

}

fs/proc/task_mmu.c

+52 −75
Original line number Diff line number Diff line
@@ -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)

{

fs/seq_file.c

+21 −7
Original line number Diff line number Diff line
@@ -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;

include/linux/kernel.h

+2 −1
Original line number Diff line number Diff line
@@ -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 */

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