Hi,
During recent discussion on LKML over SLAB vs SLUB it was suggested by
Jesper that it would be nice to have a tool to view the current
fragmentation of the slab allocators. CC list for this set is taken
from that thread.
For SLUB we have all the information for this already exposed by the
kernel and also we have a userspace tool for displaying this info:
tools/vm/slabinfo.c
Extend slabinfo to improve the fragmentation information by enabling
sorting of caches by number of partial slabs.
Also add cache list sorted in this manner to the output of `slabinfo -X`.
thanks,
Tobin.
Tobin C. Harding (4):
tools/vm/slabinfo: Order command line options
tools/vm/slabinfo: Add partial slab listing to -X
tools/vm/slabinfo: Add option to sort by partial slabs
tools/vm/slabinfo: Add sorting info to help menu
tools/vm/slabinfo.c | 118 ++++++++++++++++++++++++++------------------
1 file changed, 70 insertions(+), 48 deletions(-)
--
2.21.0
We would like to get a better view of the level of fragmentation within
the SLUB allocator. Total number of partial slabs is an indicator of
fragmentation.
Add a command line option (-P | --partial) to sort the slab list by
total number of partial slabs.
Signed-off-by: Tobin C. Harding <[email protected]>
---
tools/vm/slabinfo.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/tools/vm/slabinfo.c b/tools/vm/slabinfo.c
index 3f3a2db65794..469ff6157986 100644
--- a/tools/vm/slabinfo.c
+++ b/tools/vm/slabinfo.c
@@ -111,7 +111,7 @@ static void fatal(const char *x, ...)
static void usage(void)
{
printf("slabinfo 4/15/2011. (c) 2007 sgi/(c) 2011 Linux Foundation.\n\n"
- "slabinfo [-aABDefhilLnorsStTUvXz1] [N=K] [-dafzput] [slab-regexp]\n"
+ "slabinfo [-aABDefhilLnoPrsStTUvXz1] [N=K] [-dafzput] [slab-regexp]\n"
"-a|--aliases Show aliases\n"
"-A|--activity Most active slabs first\n"
"-B|--Bytes Show size in bytes\n"
@@ -125,6 +125,7 @@ static void usage(void)
"-n|--numa Show NUMA information\n"
"-N|--lines=K Show the first K slabs\n"
"-o|--ops Show kmem_cache_ops\n"
+ "-P|--partial Sort by number of partial slabs\n"
"-r|--report Detailed report on single slabs\n"
"-s|--shrink Shrink slabs\n"
"-S|--Size Sort by size\n"
@@ -1361,6 +1362,7 @@ struct option opts[] = {
{ "numa", no_argument, NULL, 'n' },
{ "lines", required_argument, NULL, 'N'},
{ "ops", no_argument, NULL, 'o' },
+ { "partial", no_argument, NULL, 'p'},
{ "report", no_argument, NULL, 'r' },
{ "shrink", no_argument, NULL, 's' },
{ "Size", no_argument, NULL, 'S'},
@@ -1382,7 +1384,7 @@ int main(int argc, char *argv[])
page_size = getpagesize();
- while ((c = getopt_long(argc, argv, "aABd::DefhilLnN:orsStTUvXz1",
+ while ((c = getopt_long(argc, argv, "aABd::DefhilLnN:oPrsStTUvXz1",
opts, NULL)) != -1)
switch (c) {
case 'a':
@@ -1436,6 +1438,9 @@ int main(int argc, char *argv[])
case 'r':
show_report = 1;
break;
+ case 'P':
+ sort_partial = 1;
+ break;
case 's':
shrink = 1;
break;
--
2.21.0
get_opt() has a spurious character within the option string. Remove it
and reorder the options in alphabetic order so that it is easier to keep
the options correct. Use the same ordering for command help output and
long option handling code.
Signed-off-by: Tobin C. Harding <[email protected]>
---
tools/vm/slabinfo.c | 70 ++++++++++++++++++++++-----------------------
1 file changed, 35 insertions(+), 35 deletions(-)
diff --git a/tools/vm/slabinfo.c b/tools/vm/slabinfo.c
index 73818f1b2ef8..e9b5437b2f28 100644
--- a/tools/vm/slabinfo.c
+++ b/tools/vm/slabinfo.c
@@ -110,7 +110,7 @@ static void fatal(const char *x, ...)
static void usage(void)
{
printf("slabinfo 4/15/2011. (c) 2007 sgi/(c) 2011 Linux Foundation.\n\n"
- "slabinfo [-aADefhilnosrStTvz1LXBU] [N=K] [-dafzput] [slab-regexp]\n"
+ "slabinfo [-aABDefhilLnorsStTUvXz1] [N=K] [-dafzput] [slab-regexp]\n"
"-a|--aliases Show aliases\n"
"-A|--activity Most active slabs first\n"
"-B|--Bytes Show size in bytes\n"
@@ -131,9 +131,9 @@ static void usage(void)
"-T|--Totals Show summary information\n"
"-U|--Unreclaim Show unreclaimable slabs only\n"
"-v|--validate Validate slabs\n"
+ "-X|--Xtotals Show extended summary information\n"
"-z|--zero Include empty slabs\n"
"-1|--1ref Single reference\n"
- "-X|--Xtotals Show extended summary information\n"
"\n"
"-d | --debug Switch off all debug options\n"
@@ -1334,6 +1334,7 @@ static void xtotals(void)
struct option opts[] = {
{ "aliases", no_argument, NULL, 'a' },
{ "activity", no_argument, NULL, 'A' },
+ { "Bytes", no_argument, NULL, 'B'},
{ "debug", optional_argument, NULL, 'd' },
{ "display-activity", no_argument, NULL, 'D' },
{ "empty", no_argument, NULL, 'e' },
@@ -1341,21 +1342,20 @@ struct option opts[] = {
{ "help", no_argument, NULL, 'h' },
{ "inverted", no_argument, NULL, 'i'},
{ "slabs", no_argument, NULL, 'l' },
+ { "Loss", no_argument, NULL, 'L'},
{ "numa", no_argument, NULL, 'n' },
+ { "lines", required_argument, NULL, 'N'},
{ "ops", no_argument, NULL, 'o' },
- { "shrink", no_argument, NULL, 's' },
{ "report", no_argument, NULL, 'r' },
+ { "shrink", no_argument, NULL, 's' },
{ "Size", no_argument, NULL, 'S'},
{ "tracking", no_argument, NULL, 't'},
{ "Totals", no_argument, NULL, 'T'},
+ { "Unreclaim", no_argument, NULL, 'U'},
{ "validate", no_argument, NULL, 'v' },
+ { "Xtotals", no_argument, NULL, 'X'},
{ "zero", no_argument, NULL, 'z' },
{ "1ref", no_argument, NULL, '1'},
- { "lines", required_argument, NULL, 'N'},
- { "Loss", no_argument, NULL, 'L'},
- { "Xtotals", no_argument, NULL, 'X'},
- { "Bytes", no_argument, NULL, 'B'},
- { "Unreclaim", no_argument, NULL, 'U'},
{ NULL, 0, NULL, 0 }
};
@@ -1367,18 +1367,18 @@ int main(int argc, char *argv[])
page_size = getpagesize();
- while ((c = getopt_long(argc, argv, "aAd::Defhil1noprstvzTSN:LXBU",
+ while ((c = getopt_long(argc, argv, "aABd::DefhilLnN:orsStTUvXz1",
opts, NULL)) != -1)
switch (c) {
- case '1':
- show_single_ref = 1;
- break;
case 'a':
show_alias = 1;
break;
case 'A':
sort_active = 1;
break;
+ case 'B':
+ show_bytes = 1;
+ break;
case 'd':
set_debug = 1;
if (!debug_opt_scan(optarg))
@@ -1399,9 +1399,22 @@ int main(int argc, char *argv[])
case 'i':
show_inverted = 1;
break;
+ case 'l':
+ show_slab = 1;
+ break;
+ case 'L':
+ sort_loss = 1;
+ break;
case 'n':
show_numa = 1;
break;
+ case 'N':
+ if (optarg) {
+ output_lines = atoi(optarg);
+ if (output_lines < 1)
+ output_lines = 1;
+ }
+ break;
case 'o':
show_ops = 1;
break;
@@ -1411,33 +1424,20 @@ int main(int argc, char *argv[])
case 's':
shrink = 1;
break;
- case 'l':
- show_slab = 1;
+ case 'S':
+ sort_size = 1;
break;
case 't':
show_track = 1;
break;
- case 'v':
- validate = 1;
- break;
- case 'z':
- skip_zero = 0;
- break;
case 'T':
show_totals = 1;
break;
- case 'S':
- sort_size = 1;
- break;
- case 'N':
- if (optarg) {
- output_lines = atoi(optarg);
- if (output_lines < 1)
- output_lines = 1;
- }
+ case 'U':
+ unreclaim_only = 1;
break;
- case 'L':
- sort_loss = 1;
+ case 'v':
+ validate = 1;
break;
case 'X':
if (output_lines == -1)
@@ -1445,11 +1445,11 @@ int main(int argc, char *argv[])
extended_totals = 1;
show_bytes = 1;
break;
- case 'B':
- show_bytes = 1;
+ case 'z':
+ skip_zero = 0;
break;
- case 'U':
- unreclaim_only = 1;
+ case '1':
+ show_single_ref = 1;
break;
default:
fatal("%s: Invalid option '%c'\n", argv[0], optopt);
--
2.21.0
We would like to see how fragmented the SLUB allocator is, one window
into fragmentation is the total number of partial slabs.
Currently `slabinfo -X` shows slabs sorted by loss and by size. We can
use this option to also show slabs sorted by number of partial slabs.
Option '-X' can be used in conjunction with '-N' to control the number
of slabs shown e.g. list of top 5 slabs:
slabinfo -X -N5
Add list of slabs ordered by number of partial slabs to output of
`slabinfo -X`.
Signed-off-by: Tobin C. Harding <[email protected]>
---
tools/vm/slabinfo.c | 41 ++++++++++++++++++++++++++++-------------
1 file changed, 28 insertions(+), 13 deletions(-)
diff --git a/tools/vm/slabinfo.c b/tools/vm/slabinfo.c
index e9b5437b2f28..3f3a2db65794 100644
--- a/tools/vm/slabinfo.c
+++ b/tools/vm/slabinfo.c
@@ -79,6 +79,7 @@ int sort_size;
int sort_active;
int set_debug;
int show_ops;
+int sort_partial;
int show_activity;
int output_lines = -1;
int sort_loss;
@@ -1047,6 +1048,8 @@ static void sort_slabs(void)
result = slab_activity(s1) < slab_activity(s2);
else if (sort_loss)
result = slab_waste(s1) < slab_waste(s2);
+ else if (sort_partial)
+ result = s1->partial < s2->partial;
else
result = strcasecmp(s1->name, s2->name);
@@ -1307,27 +1310,39 @@ static void output_slabs(void)
}
}
+static void _xtotals(char *heading, char *underline,
+ int loss, int size, int partial)
+{
+ printf("%s%s", heading, underline);
+ line = 0;
+ sort_loss = loss;
+ sort_size = size;
+ sort_partial = partial;
+ sort_slabs();
+ output_slabs();
+}
+
static void xtotals(void)
{
+ char *heading, *underline;
+
totals();
link_slabs();
rename_slabs();
- printf("\nSlabs sorted by size\n");
- printf("--------------------\n");
- sort_loss = 0;
- sort_size = 1;
- sort_slabs();
- output_slabs();
+ heading = "\nSlabs sorted by size\n";
+ underline = "--------------------\n";
+ _xtotals(heading, underline, 0, 1, 0);
+
+ heading = "\nSlabs sorted by loss\n";
+ underline = "--------------------\n";
+ _xtotals(heading, underline, 1, 0, 0);
+
+ heading = "\nSlabs sorted by number of partial slabs\n";
+ underline = "---------------------------------------\n";
+ _xtotals(heading, underline, 0, 0, 1);
- printf("\nSlabs sorted by loss\n");
- printf("--------------------\n");
- line = 0;
- sort_loss = 1;
- sort_size = 0;
- sort_slabs();
- output_slabs();
printf("\n");
}
--
2.21.0
Passing more than one sorting option has undefined behaviour.
Add an explicit statement as such to the help menu, this also has the
advantage of highlighting all the sorting options.
Signed-off-by: Tobin C. Harding <[email protected]>
---
tools/vm/slabinfo.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/vm/slabinfo.c b/tools/vm/slabinfo.c
index 469ff6157986..68092d15e12b 100644
--- a/tools/vm/slabinfo.c
+++ b/tools/vm/slabinfo.c
@@ -148,6 +148,8 @@ static void usage(void)
" p | P Poisoning\n"
" u | U Tracking\n"
" t | T Tracing\n"
+
+ "\nSorting options (--Loss, --Size, --Partial) are mutually exclusive\n"
);
}
--
2.21.0