Dear all,

I have server Dell R510 running CentOS 6.2 with kernel 2.6.32-220.2.1.el6.x86_64, yesterday the server reboot by itself, I got crash report email from the server with these information

==================

Duplicate check
=====


Common information
=====
package
-----
kernel

architecture
-----
x86_64

kernel
-----
2.6.32-220.2.1.el6.x86_64



Additional information
=====
kernel_tainted_long
-----
Taint on warning.

time
-----
1371900340

backtrace
-----
WARNING: at kernel/sched.c:5914 thread_return+0x232/0x79d() (Not tainted)
Hardware name: PowerEdge R510
Modules linked in: autofs4 sunrpc ipt_REDIRECT iptable_nat nf_nat xt_MARK iptable_mangle ipt_REJECT ipt_LOG nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 power_meter dcdbas microcode serio_raw iTCO_wdt iTCO_vendor_support i7core_edac edac_core sg ses enclosure tg3 bnx2 ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif pata_acpi ata_generic ata_piix megaraid_sas dm_mirror dm_region_hash dm_log dm_mod [last unloaded: speedstep_lib]
Pid: 2852, comm: mysqld Not tainted 2.6.32-220.2.1.el6.x86_64 #1
Call Trace:
[<ffffffff81069997>] ? warn_slowpath_common+0x87/0xc0
[<ffffffff810699ea>] ? warn_slowpath_null+0x1a/0x20
[<ffffffff814eccc5>] ? thread_return+0x232/0x79d
[<ffffffff811bf282>] ? read_events+0x2e2/0x450
[<ffffffff8105e770>] ? default_wake_function+0x0/0x20
[<ffffffff811bd9c0>] ? timeout_func+0x0/0x20
[<ffffffff811bf45b>] ? sys_io_getevents+0x6b/0xb0
[<ffffffff8100b0f2>] ? system_call_fastpath+0x16/0x1b


hostname
-----
r3.bisan.com

component
-----
kernel

kernel_tainted
-----
512

reason
-----
WARNING: at kernel/sched.c:5914 thread_return+0x232/0x79d() (Not tainted)

analyzer
-----
Kerneloops

kernel_tainted_short
-----
---------W

cmdline
-----
ro root=UUID=653648d2-8443-4bd4-81fe-c2a4ca4b226c rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=131M@0M rhgb quiet

os_release
-----
CentOS release 6.2 (Final)


======================

why this happened, please help me if the problem from OS and kernel or it is a hardware issue from the server

Thanks.

CentOS 6 has been at Update 4 for quite some time now. To illustrate that: your kernel version was released in December 2011. Updates contain newer kernel versions that may fix bugs, so keeping your system up to date seems the first thing to do. See also http://bugs.centos.org/view.php?id=5371 which references RHEL KB article and PCIE stuffs to try.