Hi,
I have found a regression created by my 99d71ad.
I have fixed it, and have tested again.
[Test Results]
With 99d71ad:
# slabtop -o
Active / Total Objects (% used) : 51108440 / 51120763 (100.0%)
Active / Total Slabs (% used) : 129448 / 129448 (100.0%)
Active / Total Caches (% used) : 76 / 110 (69.1%)
Active / Total Size (% used) : 550881.62K / 556812.11K (98.9%)
Minimum / Average / Maximum Object : 0.01K / 0.01K / 8.00K
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
50085888 50085888 100% 0.01K 97824 512 391296K kmalloc-8
<-- correct %use (fixed original issue)
399483 399483 100% 0.19K 19023 21 76092K dentry
129536 128653 0% 0.03K 1012 128 4048K kmalloc-32
<-- wrong %use (created regression)
127500 127500 100% 0.02K 750 170 3000K scsi_data_buffer
99200 99200 100% 0.06K 1550 64 6200K kmalloc-64
57344 57344 100% 0.02K 224 256 896K kmalloc-16
49011 49011 100% 0.08K 961 51 3844K Acpi-State
36735 32637 0% 1.06K 2449 15 39184K xfs_inode
<-- wrong %use (created regression)
29068 23208 0% 0.15K 1118 26 4472K xfs_ili
<-- wrong %use (created regression)
29055 29055 100% 0.10K 745 39 2980K buffer_head
17272 17272 100% 0.12K 508 34 2032K kernfs_node_cache
14308 14308 100% 0.55K 1022 14 8176K inode_cache
5754 5754 100% 0.57K 411 14 3288K radix_tree_node
5250 5250 100% 0.09K 125 42 500K kmalloc-96
4116 3988 0% 0.19K 196 21 784K cred_jar
<-- wrong %use (created regression)
3072 3072 100% 0.06K 48 64 192K anon_vma_chain
Without 99d71ad:
# slabtop -o
Active / Total Objects (% used) : 51111248 / 51123147 (100.0%)
Active / Total Slabs (% used) : 129522 / 129522 (100.0%)
Active / Total Caches (% used) : 76 / 110 (69.1%)
Active / Total Size (% used) : 551429.75K / 557128.55K (99.0%)
Minimum / Average / Maximum Object : 0.01K / 0.01K / 8.00K
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
50085888 50085888 14% 0.01K 97824 512 391296K kmalloc-8
<-- wrong %use (original issue)
400029 400029 100% 0.19K 19049 21 76196K dentry
129536 128653 99% 0.03K 1012 128 4048K kmalloc-32
<-- correct %use (no regression)
127500 127500 100% 0.02K 750 170 3000K scsi_data_buffer
99584 99584 100% 0.06K 1556 64 6224K kmalloc-64
57600 57600 100% 0.02K 225 256 900K kmalloc-16
49215 49215 100% 0.08K 965 51 3860K Acpi-State
36735 32812 89% 1.06K 2449 15 39184K xfs_inode
<-- correct %use (no regression)
29640 29640 100% 0.10K 760 39 3040K buffer_head
29068 23381 80% 0.15K 1118 26 4472K xfs_ili
<-- correct %use (no regression)
17272 17272 100% 0.12K 508 34 2032K kernfs_node_cache
14308 14308 100% 0.55K 1022 14 8176K inode_cache
5838 5838 100% 0.57K 417 14 3336K radix_tree_node
5250 5250 100% 0.09K 125 42 500K kmalloc-96
4431 4347 98% 0.19K 211 21 844K cred_jar
<-- correct %use (no regression)
3072 3072 100% 0.06K 48 64 192K anon_vma_chain
This fix:
# slabtop -o
Active / Total Objects (% used) : 51166965 / 51177637 (100.0%)
Active / Total Slabs (% used) : 132006 / 132006 (100.0%)
Active / Total Caches (% used) : 76 / 110 (69.1%)
Active / Total Size (% used) : 561516.01K / 566932.82K (99.0%)
Minimum / Average / Maximum Object : 0.01K / 0.01K / 8.00K
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
50085888 50085888 100% 0.01K 97824 512 391296K kmalloc-8
<-- correct %use (fixed original issue)
450744 450744 100% 0.19K 21464 21 85856K dentry
130944 130632 99% 0.03K 1023 128 4092K kmalloc-32
<-- correct %use (fixed regression)
127500 127500 100% 0.02K 750 170 3000K scsi_data_buffer
100032 100032 100% 0.06K 1563 64 6252K kmalloc-64
57600 57600 100% 0.02K 225 256 900K kmalloc-16
49419 49419 100% 0.08K 969 51 3876K Acpi-State
36735 32951 89% 1.06K 2449 15 39184K xfs_inode
<-- correct %use (fixed regression)
31122 31122 100% 0.10K 798 39 3192K buffer_head
29068 23868 82% 0.15K 1118 26 4472K xfs_ili
<-- correct %use (fixed regression)
17272 17272 100% 0.12K 508 34 2032K kernfs_node_cache
14308 14308 100% 0.55K 1022 14 8176K inode_cache
6076 6076 100% 0.57K 434 14 3472K radix_tree_node
5292 5292 100% 0.09K 126 42 504K kmalloc-96
4305 4204 97% 0.19K 205 21 820K cred_jar
<-- correct %use (fixed regression)
3200 3200 100% 0.06K 50 64 200K anon_vma_chain
Thanks,
Takayuki NagataFrom 991ed5b25d2604ad8e4106861f88816d31e96a13 Mon Sep 17 00:00:00 2001
From: Takayuki Nagata <tnagata@xxxxxxxxxx>
Date: Wed, 27 Jul 2016 17:29:15 +0900
Subject: [PATCH 1/2] Revert "bprocps: fix order of operations for %use of
slabinfo"
This reverts commit 99d71ad5810b8fbfab5c4c6be97f3e86953b6157.
When nr_active_objs / nr_objs is calculated, the result will be 1
or 0 since the variables are integer. So the commit is wrong.
---
proc/slab.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/proc/slab.c b/proc/slab.c
index 2d7f967..444b79c 100644
--- a/proc/slab.c
+++ b/proc/slab.c
@@ -179,7 +179,7 @@ static int parse_slabinfo20(struct slab_info **list, struct
slab_stat *stats,
curr->cache_size = (unsigned long)curr->nr_slabs *
curr->pages_per_slab * page_size;
if (curr->nr_objs) {
- curr->use = 100 * (curr->nr_active_objs /
curr->nr_objs);
+ curr->use = 100 * curr->nr_active_objs / curr->nr_objs;
stats->nr_active_caches++;
} else
curr->use = 0;
--
2.7.4
From 40fd010ff285a0ef3762f60c4eb3caceb6a795f1 Mon Sep 17 00:00:00 2001
From: Takayuki Nagata <tnagata@xxxxxxxxxx>
Date: Thu, 4 Aug 2016 18:06:06 +0900
Subject: [PATCH 2/2] libprocps: use float to calculate %use of slabtop
In some environments, 100 * nr_active_objs is calculated at first,
and the result of lower 32bits is divided by nr_objs. This occurs
even in a 64-bit architecture. So nr_active_objes > 42949672, %use
will be incorrect.
This fix casts type of nr_active_objs to float to calculate
correctly the %use in 32-bit/64-bit architectures.
Signed-off-by: Takayuki Nagata <tnagata@xxxxxxxxxx>
---
proc/slab.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/proc/slab.c b/proc/slab.c
index 444b79c..4917741 100644
--- a/proc/slab.c
+++ b/proc/slab.c
@@ -179,7 +179,7 @@ static int parse_slabinfo20(struct slab_info **list, struct
slab_stat *stats,
curr->cache_size = (unsigned long)curr->nr_slabs *
curr->pages_per_slab * page_size;
if (curr->nr_objs) {
- curr->use = 100 * curr->nr_active_objs / curr->nr_objs;
+ curr->use = 100 * (float)curr->nr_active_objs /
curr->nr_objs;
stats->nr_active_caches++;
} else
curr->use = 0;
@@ -258,7 +258,7 @@ static int parse_slabinfo11(struct slab_info **list, struct
slab_stat *stats,
curr->cache_size = (unsigned long)curr->nr_slabs *
curr->pages_per_slab * page_size;
if (curr->nr_objs) {
- curr->use = 100 * curr->nr_active_objs / curr->nr_objs;
+ curr->use = 100 * (float)curr->nr_active_objs /
curr->nr_objs;
stats->nr_active_caches++;
} else
curr->use = 0;
--
2.7.4
