Subject: 4.4.0 - e1000e - possible power management issue

From: Nikola Ciprich <[email-masked]>
Date: Tue, 19 Apr 2016 21:53:44 +0200

Hi,

after upgrading our firewall from 4.1.17 to 4.4.0, we've noticed quite a performance
drop.. Slight network load seems to cause high CPU load..

running perf of almost idle system shows:

             samples  pcnt function                                DSO
             _______ _____ _______________________________________ ___________________________________________________________________________

              631.00 20.7% e1000_power_down_phy_copper_80003es2lan /lib/modules/4.4.0lb6.01/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
              191.00  6.3% do_raw_spin_lock                        [kernel.kallsyms]                                                          
              165.00  5.4% ipt_register_table                      /lib/modules/4.4.0lb6.01/kernel/net/ipv4/netfilter/ip_tables.ko            
              119.00  3.9% cache_init                              /usr/sbin/netstat-probe                                                    
              118.00  3.9% __memset_sse2                           /lib64/libc-2.12.so                                                        
               88.00  2.9% cache_write_packet                      /usr/sbin/netstat-probe                                                    
               41.00  1.3% __fget                                  [kernel.kallsyms]                                                          
               40.00  1.3% memcpy                                  [kernel.kallsyms]                                                          

when there is some network traffic, e1000_power_down_phy_copper_80003es2lan jumps to much higher
numbers.. as far as I understand the code, this seems suspicious to me..

Anyone hit the same problem?

I can try upgrading to 4.4.8-rc1 tomorrow or reverting to 4.1.17

lspci of the box adapters:

05:00.0 Ethernet controller: Intel Corporation 82573E Gigabit Ethernet Controller (Copper) (rev 03)
07:00.0 Ethernet controller: Intel Corporation 82573L Gigabit Ethernet Controller
09:00.0 Ethernet controller: Intel Corporation 82573L Gigabit Ethernet Controller
0b:00.0 Ethernet controller: Intel Corporation 82573L Gigabit Ethernet Controller

BR

nik

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Ing. Nikola CIPRICH
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