* [RFC][PATCH 2/4] break out unit selection from string_get_size()
2011-09-30 18:02 [RFC][PATCH 1/4] break up string_get_size() Dave Hansen
@ 2011-09-30 18:02 ` Dave Hansen
2011-09-30 18:54 ` H. Peter Anvin
2011-09-30 18:02 ` [RFC][PATCH 3/4] add seq_print_size() function Dave Hansen
2011-09-30 18:02 ` [RFC][PATCH 4/4] show page size in /proc/$pid/numa_maps Dave Hansen
2 siblings, 1 reply; 5+ messages in thread
From: Dave Hansen @ 2011-09-30 18:02 UTC (permalink / raw)
To: linux-mm; +Cc: linux-kernel, rientjes, James.Bottomley, hpa, Dave Hansen
string_get_size() can really only print things in a single
format. You're always stuck with a space, and it will
always zero-pad the decimal places:
4.00 KiB
40.0 KiB
400 KiB
Printing page sizes in decimal KiB does not make much sense
since they are always nice powers of two. But,
string_get_size() does have some nice code for selecting
the right units and doing the division.
This breaks that nice code out so that we can reuse it.
find_size_units() is a bit of a funky function since it has
so many outputs. I don't think it's _too_ crazy though.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
---
linux-2.6.git-dave/include/linux/string_helpers.h | 3
linux-2.6.git-dave/lib/string_helpers.c | 67 +++++++++++++++-------
2 files changed, 50 insertions(+), 20 deletions(-)
diff -puN include/linux/string_helpers.h~break-up-string_get_size-1 include/linux/string_helpers.h
--- linux-2.6.git/include/linux/string_helpers.h~break-up-string_get_size-1 2011-09-30 10:47:14.794753824 -0700
+++ linux-2.6.git-dave/include/linux/string_helpers.h 2011-09-30 10:47:14.806753800 -0700
@@ -10,6 +10,9 @@ enum string_size_units {
STRING_UNITS_2, /* use binary powers of 2^10 */
};
+u64 find_size_units(u64 *size, const enum string_size_units units,
+ const char **unit_str);
+
int string_get_size(u64 size, enum string_size_units units,
char *buf, int len);
diff -puN lib/string_helpers.c~break-up-string_get_size-1 lib/string_helpers.c
--- linux-2.6.git/lib/string_helpers.c~break-up-string_get_size-1 2011-09-30 10:47:14.798753816 -0700
+++ linux-2.6.git-dave/lib/string_helpers.c 2011-09-30 10:47:14.806753800 -0700
@@ -20,6 +20,49 @@ static int calc_sf_digit_room(u64 size)
return digits;
}
+static const char *units_10[] = { "B", "kB", "MB", "GB", "TB", "PB",
+ "EB", "ZB", "YB", NULL};
+static const char *units_2[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB",
+ "EiB", "ZiB", "YiB", NULL };
+
+static const char **units_str[] = {
+ [STRING_UNITS_10] = units_10,
+ [STRING_UNITS_2] = units_2,
+};
+static const unsigned int divisor[] = {
+ [STRING_UNITS_10] = 1000,
+ [STRING_UNITS_2] = 1024,
+};
+
+/**
+ * string_get_size - helper function for printing numbers
+ * @size: number to be printed (modified)
+ * @units: units to use (powers of 1000 or 1024)
+ * @unit_str: unit is returned in this string
+ * returns: remainder from divisions
+ *
+ * The goal here is to return a number in @size which has
+ * only 3 significant figures, along with the unit pointed
+ * to by unit_str which is necessary to make that happen.
+ *
+ * We return the remainder so that the caller does not have
+ * to repeat the division operations themselves.
+ */
+u64 find_size_units(u64 *size, const enum string_size_units units,
+ const char **unit_str)
+{
+ u64 remainder = 0;
+ int i = 0;
+
+ while (*size >= divisor[units] && units_str[units][i]) {
+ remainder = do_div(*size, divisor[units]);
+ i++;
+ }
+ *unit_str = units_str[units][i];
+ return remainder;
+}
+EXPORT_SYMBOL(find_size_units);
+
/**
* string_get_size - get the size in the specified units
* @size: The size to be converted
@@ -35,30 +78,14 @@ static int calc_sf_digit_room(u64 size)
int string_get_size(u64 size, const enum string_size_units units,
char *buf, int len)
{
- const char *units_10[] = { "B", "kB", "MB", "GB", "TB", "PB",
- "EB", "ZB", "YB", NULL};
- const char *units_2[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB",
- "EiB", "ZiB", "YiB", NULL };
- const char **units_str[] = {
- [STRING_UNITS_10] = units_10,
- [STRING_UNITS_2] = units_2,
- };
- const unsigned int divisor[] = {
- [STRING_UNITS_10] = 1000,
- [STRING_UNITS_2] = 1024,
- };
- int i, j;
+ int j;
u64 remainder = 0;
char tmp[8];
+ const char *unit_str = "";
tmp[0] = '\0';
- i = 0;
if (size >= divisor[units]) {
- while (size >= divisor[units] && units_str[units][i]) {
- remainder = do_div(size, divisor[units]);
- i++;
- }
-
+ remainder = find_size_units(&size, units, &unit_str);
j = calc_sf_digit_room(size);
if (j) {
remainder *= 1000;
@@ -70,7 +97,7 @@ int string_get_size(u64 size, const enum
}
snprintf(buf, len, "%lld%s %s", (unsigned long long)size,
- tmp, units_str[units][i]);
+ tmp, unit_str);
return 0;
}
_
--
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^ permalink raw reply [flat|nested] 5+ messages in thread* [RFC][PATCH 3/4] add seq_print_size() function
2011-09-30 18:02 [RFC][PATCH 1/4] break up string_get_size() Dave Hansen
2011-09-30 18:02 ` [RFC][PATCH 2/4] break out unit selection from string_get_size() Dave Hansen
@ 2011-09-30 18:02 ` Dave Hansen
2011-09-30 18:02 ` [RFC][PATCH 4/4] show page size in /proc/$pid/numa_maps Dave Hansen
2 siblings, 0 replies; 5+ messages in thread
From: Dave Hansen @ 2011-09-30 18:02 UTC (permalink / raw)
To: linux-mm; +Cc: linux-kernel, rientjes, James.Bottomley, hpa, Dave Hansen
In order to get nice, human-readable output, we are going to
use MiB/KiB, etc... in numa_maps. Introduce a helper to do
the conversion from a raw integer over to a string.
I thought about doing this as a new printk() format specifier.
That would be interesting, but it's hard to argue with this
since it's so short and sweet.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
---
linux-2.6.git-dave/fs/seq_file.c | 15 +++++++++++++++
linux-2.6.git-dave/include/linux/seq_file.h | 3 +++
2 files changed, 18 insertions(+)
diff -puN fs/seq_file.c~add-seq_print_size fs/seq_file.c
--- linux-2.6.git/fs/seq_file.c~add-seq_print_size 2011-09-30 10:52:22.302140723 -0700
+++ linux-2.6.git-dave/fs/seq_file.c 2011-09-30 10:52:22.322140685 -0700
@@ -386,6 +386,21 @@ int seq_printf(struct seq_file *m, const
}
EXPORT_SYMBOL(seq_printf);
+/*
+ * Prints output with MiB/MB/KB/etc... suffixes
+ */
+int seq_print_size(struct seq_file *seq, u64 size,
+ const enum string_size_units units)
+{
+ int ret;
+ u64 remainder;
+ char *size_str;
+ remainder = find_size_units(&size, units, &size_str);
+ ret += seq_printf(seq, "%llu", size);
+ ret += seq_puts(seq, size_str);
+ return ret;
+}
+
/**
* mangle_path - mangle and copy path to buffer beginning
* @s: buffer start
diff -puN include/linux/seq_file.h~add-seq_print_size include/linux/seq_file.h
--- linux-2.6.git/include/linux/seq_file.h~add-seq_print_size 2011-09-30 10:52:22.314140700 -0700
+++ linux-2.6.git-dave/include/linux/seq_file.h 2011-09-30 10:52:22.322140685 -0700
@@ -3,6 +3,7 @@
#include <linux/types.h>
#include <linux/string.h>
+#include <linux/string_helpers.h>
#include <linux/mutex.h>
#include <linux/cpumask.h>
#include <linux/nodemask.h>
@@ -83,6 +84,8 @@ int seq_escape(struct seq_file *, const
int seq_putc(struct seq_file *m, char c);
int seq_puts(struct seq_file *m, const char *s);
int seq_write(struct seq_file *seq, const void *data, size_t len);
+int seq_print_size(struct seq_file *seq, u64 size,
+ const enum string_size_units units);
int seq_printf(struct seq_file *, const char *, ...)
__attribute__ ((format (printf,2,3)));
_
--
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^ permalink raw reply [flat|nested] 5+ messages in thread* [RFC][PATCH 4/4] show page size in /proc/$pid/numa_maps
2011-09-30 18:02 [RFC][PATCH 1/4] break up string_get_size() Dave Hansen
2011-09-30 18:02 ` [RFC][PATCH 2/4] break out unit selection from string_get_size() Dave Hansen
2011-09-30 18:02 ` [RFC][PATCH 3/4] add seq_print_size() function Dave Hansen
@ 2011-09-30 18:02 ` Dave Hansen
2 siblings, 0 replies; 5+ messages in thread
From: Dave Hansen @ 2011-09-30 18:02 UTC (permalink / raw)
To: linux-mm; +Cc: linux-kernel, rientjes, James.Bottomley, hpa, Dave Hansen
The output of /proc/$pid/numa_maps is in terms of number of pages
like anon=22 or dirty=54. Here's some output:
7f4680000000 default file=/hugetlb/bigfile anon=50 dirty=50 N0=50
7f7659600000 default file=/anon_hugepage\040(deleted) anon=50 dirty=50 N0=50
7fff8d425000 default stack anon=50 dirty=50 N0=50
Looks like we have a stack and a couple of anonymous hugetlbfs
areas page which both use the same amount of memory. They don't.
The 'bigfile' uses 1GB pages and takes up ~50GB of space. The
anon_hugepage uses 2MB pages and takes up ~100MB of space while
the stack uses normal 4k pages. You can go over to smaps to
figure out what the page size _really_ is with KernelPageSize
or MMUPageSize. But, I think this is a pretty nasty and
counterintuitive interface as it stands.
The following patch adds a pagesize= field. Note that this only
shows the kernel's notion of page size. For transparent
hugepages, it still shows the base page size. Here's some real
output. Note the anon_hugepage in there.
# cat /proc/`pidof memknobs`/numa_maps
00400000 default file=/root/memknobs pagesize=4KiB dirty=3 active=2 N0=3
00602000 default file=/root/memknobs pagesize=4KiB anon=1 dirty=1 N0=1
00603000 default file=/root/memknobs pagesize=4KiB anon=1 dirty=1 N0=1
00604000 default heap pagesize=4KiB anon=6 dirty=6 N0=6
7f6766216000 default file=/lib/libc-2.9.so pagesize=4KiB mapped=98 mapmax=25 active=97 N0=98
7f676637e000 default file=/lib/libc-2.9.so
7f676657e000 default file=/lib/libc-2.9.so pagesize=4KiB anon=4 dirty=4 N0=4
7f6766582000 default file=/lib/libc-2.9.so pagesize=4KiB anon=1 dirty=1 N0=1
7f6766583000 default pagesize=4KiB anon=3 dirty=3 N0=3
7f6766588000 default file=/lib/ld-2.9.so pagesize=4KiB mapped=25 mapmax=24 N0=25
7f676679d000 default pagesize=4KiB anon=2 dirty=2 N0=2
7f67667a3000 default pagesize=4KiB anon=4 dirty=4 N0=4
7f67667a7000 default file=/lib/ld-2.9.so pagesize=4KiB anon=1 dirty=1 N0=1
7f67667a8000 default file=/lib/ld-2.9.so pagesize=4KiB anon=1 dirty=1 N0=1
7f6766800000 default file=/anon_hugepage\040(deleted) pagesize=2MiB anon=10 dirty=10 N0=10
7fff5b948000 default stack pagesize=4KiB anon=2 dirty=2 N0=2
7fff5b96d000 default
Signed-off-by: Dave Haneen <dave@linux.vnet.ibm.com>
---
linux-2.6.git-dave/fs/proc/task_mmu.c | 5 +++++
1 file changed, 5 insertions(+)
diff -puN fs/proc/task_mmu.c~show-page-size fs/proc/task_mmu.c
--- linux-2.6.git/fs/proc/task_mmu.c~show-page-size 2011-09-30 10:53:09.166048432 -0700
+++ linux-2.6.git-dave/fs/proc/task_mmu.c 2011-09-30 10:53:09.174048416 -0700
@@ -1044,6 +1044,11 @@ static int show_numa_map(struct seq_file
if (!md->pages)
goto out;
+ /* Only interesting for hugetlbfs pages.
+ * Transparent hugepages are still pagesize=4k */
+ seq_puts(m, " pagesize=");
+ seq_print_size(m, vma_kernel_pagesize(vma), STRING_UNITS_2);
+
if (md->anon)
seq_printf(m, " anon=%lu", md->anon);
_
--
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^ permalink raw reply [flat|nested] 5+ messages in thread