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
v2: rename seq_put_decimal_ull_align into seq_put_decimal_ull_width
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrei Vagin <avagin@xxxxxxxxxx>
---
fs/proc/meminfo.c | 15 +-----
fs/proc/task_mmu.c | 127 +++++++++++++++++++----------------------------
fs/seq_file.c | 28 ++++++++---
include/linux/kernel.h | 3 +-
include/linux/seq_file.h | 2 +
lib/vsprintf.c | 18 +++++--
6 files changed, 92 insertions(+), 101 deletions(-)
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 6bb20f864259..65a72ab57471 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -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);
}
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index b66fc8de7d34..3026feda0432 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -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)
{
diff --git a/fs/seq_file.c b/fs/seq_file.c
index f36ab451ade2..e6ec14a02a52 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -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;
@@ -695,10 +700,13 @@ 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;
- 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;
@@ -708,6 +716,12 @@ 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);
/**
@@ -777,7 +791,7 @@ void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num
num = -num;
}
- 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;
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index ce51455e2adf..8c621e74526a 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -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 */
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 440f1351ad57..71d6f643b9d7 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -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);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index d7a708f82559..942b5234a59b 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -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 */
--
2.13.6
