Bug 205541

Summary:	SWAP is not released once used causing OOM
Product:	Memory Management	Reporter:	skaushik (skaushik)
Component:	Other	Assignee:	Andrew Morton (akpm)
Status:	NEW ---
Severity:	blocking	CC:	skaushik
Priority:	P1
Hardware:	Intel
OS:	Linux
Kernel Version:	3.10.0-693 and 3.10.0-957	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	few command O/p /proc/sys/vm and kernel tar

Description skaushik 2019-11-15 19:51:17 UTC

Created attachment 285937 [details]
few command O/p

may be Bug 40402 could relate to my problem That's for old kernel. We are in process of upgrading Server dfrom CentOS 6 to 7 . And decided to go with 

# cat /etc/redhat-release 
CentOS Linux release 7.4.1708 (Core) 
# uname -a
Linux ki205-283 3.10.0-957.10.1.el7.x86_64 #1 SMP Mon Mar 18 15:06:45 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

tested on Hardware :

Manufacturer: Dell Inc. 
Product Name: PowerEdge C6420

Attaching few details in the attachment if that could help

Comment 1 skaushik 2019-11-15 19:52:58 UTC

Created attachment 285939 [details]
/proc/sys/vm and kernel tar

Comment 2 skaushik 2019-11-16 00:00:14 UTC

I continuously running a check which result in below o/p I recieved another OOM 30 min before still my swap is 100% full. 


********************************************

============= Messages Logs ================
Nov 15 15:38:56 XXXXXXXX kernel: [1812954.358554] wrapper invoked oom-killer: gfp_mask=0x201da, order=0, oom_score_adj=0
Nov 15 15:38:56 XXXXXXXX kernel: wrapper invoked oom-killer: gfp_mask=0x201da, order=0, oom_score_adj=0

============= ls -l /root/httpcore ================
total 0

============= sysctl parametter  ================
vm.overcommit_ratio = 80
vm.panic_on_oom = 0
kernel.panic = 0
vm.vfs_cache_pressure = 700
vm.swappiness = 10

============= Corelimit  ================
core
core file size          (blocks, -c) unlimited

============= Committed memory  ================
CommitLimit:    161229308 kB
Committed_AS:   137328600 kB

============= free o/p in MB    ================
              total        used        free      shared  buff/cache   available
Mem:         191693       81088      107602         627        3001      108808
Swap:          4095        4088           7

============= httpd COunt   ================
    188    1505   12027

============= Serverhealth  ================


	======================================================
				SYSTEM INFO
	======================================================
 HOSTNAME : XXXXXXXX					  
 LINUX_FLAVOUR : CentOS Linux release 7.4.1708 (Core)		 KERNEL_VERSION : 3.10.0 
 SYSTEM_MANUFACTURER : Dell Inc.			 BIOS_VERSION :  2.1.6 
 TOTAL_N_CORE_COUNT : 24				 UPTIME : 21 days,  1:01 
 
			PUPPETENV :  RT_325449 


	======================================================
				SYSTEM STATS
	======================================================
 LOAD_AVG : 20.82 20.57 20.91 25/1131 32440		 LOAD_AVG_PCT : 87.0 
 MemTotal : 196293764					 MemUsed_pct : 44.0 
 SwapTotal : 4194300					 SwapUsed_pct : 100.0 



	======================================================
				SYSTEM Network STATS
	======================================================
 TCP_inuse : 38251			 TCP_orphan : 0 
 UDP_inuse : 13				 UDP_mem : 4 


********************************************


After 30 min 


[15:53:43] ki210-284:~# free -m
              total        used        free      shared  buff/cache   available
Mem:         191693       88811       99252         629        3629      101086
Swap:          4095        4085          10