[PATCH 5.4 321/389] tools/vm/slabinfo: use alphabetic order when two values are equal

Greg Kroah-Hartman
2022-08-23T11:54:10Z

From: Yuanzheng Song <songyuanzheng@huawei.com>

commit 4f5ceb8851f0081af54313abbf56de1615911faf upstream.

When the number of partial slabs in each cache is the same (e.g., the
value are 0), the results of the `slabinfo -X -N5` and `slabinfo -P -N5`
are different.

/ # slabinfo -X -N5
...
Slabs sorted by number of partial slabs
---------------------------------------
Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg
inode_cache 15180 392 6217728 758/0/1 20 1 0 95 a
kernfs_node_cache 22494 88 2002944 488/0/1 46 0 0 98
shmem_inode_cache 663 464 319488 38/0/1 17 1 0 96
biovec-max 50 3072 163840 4/0/1 10 3 0 93 A
dentry 19050 136 2600960 633/0/2 30 0 0 99 a

/ # slabinfo -P -N5
Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg
bdev_cache 32 984 32.7K 1/0/1 16 2 0 96 Aa
ext4_inode_cache 42 752 32.7K 1/0/1 21 2 0 96 a
dentry 19050 136 2.6M 633/0/2 30 0 0 99 a
TCPv6 17 1840 32.7K 0/0/1 17 3 0 95 A
RAWv6 18 856 16.3K 0/0/1 18 2 0 94 A

This problem is caused by the sort_slabs(). So let's use alphabetic order
when two values are equal in the sort_slabs().

By the way, the content of the `slabinfo -h` is not aligned because the

`-P|--partial Sort by number of partial slabs`

uses tabs instead of spaces. So let's use spaces instead of tabs to fix
it.

Link: https://lkml.kernel.org/r/20220528063117.935158-1-songyuanzheng@huawei.com
Fixes: 1106b205a3fe ("tools/vm/slabinfo: add partial slab listing to -X")
Signed-off-by: Yuanzheng Song <songyuanzheng@huawei.com>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/vm/slabinfo.c | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)

--- a/tools/vm/slabinfo.c
+++ b/tools/vm/slabinfo.c
@@ -125,7 +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"
+ "-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"
@@ -1045,15 +1045,27 @@ static void sort_slabs(void)
for (s2 = s1 + 1; s2 < slabinfo + slabs; s2++) {
int result;

- if (sort_size)
- result = slab_size(s1) < slab_size(s2);
- else if (sort_active)
- 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
+ if (sort_size) {
+ if (slab_size(s1) == slab_size(s2))
+ result = strcasecmp(s1->name, s2->name);
+ else
+ result = slab_size(s1) < slab_size(s2);
+ } else if (sort_active) {
+ if (slab_activity(s1) == slab_activity(s2))
+ result = strcasecmp(s1->name, s2->name);
+ else
+ result = slab_activity(s1) < slab_activity(s2);
+ } else if (sort_loss) {
+ if (slab_waste(s1) == slab_waste(s2))
+ result = strcasecmp(s1->name, s2->name);
+ else
+ result = slab_waste(s1) < slab_waste(s2);
+ } else if (sort_partial) {
+ if (s1->partial == s2->partial)
+ result = strcasecmp(s1->name, s2->name);
+ else
+ result = s1->partial < s2->partial;
+ } else
result = strcasecmp(s1->name, s2->name);

if (show_inverted)