[PATCH 0/4] tools/vm/slabinfo: Add fragmentation output

[PATCH 0/4] tools/vm/slabinfo: Add fragmentation output

[Tobin C. Harding]

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

[PATCH 1/4] tools/vm/slabinfo: Order command line options

[Tobin C. Harding]

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 <tobin@kernel.org>
---
 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

[PATCH 2/4] tools/vm/slabinfo: Add partial slab listing to -X

[Tobin C. Harding]

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 <tobin@kernel.org>
---
 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

[PATCH 3/4] tools/vm/slabinfo: Add option to sort by partial slabs

[Tobin C. Harding]

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 <tobin@kernel.org>
---
 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

[PATCH 4/4] tools/vm/slabinfo: Add sorting info to help menu

[Tobin C. Harding]

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 <tobin@kernel.org>
---
 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