Re: packetloss, on e1000e worse than r8169?

[Eric Dumazet <dada1@cosmosbay.com>]

Denys Fedoryshchenko a e'crit :
> On Mon, 16 Jun 2008 23:29:01 +0200, Eric Dumazet wrote
>> Denys Fedoryshchenko a [UTF-8?]ц╘crit :
>>>> Are you sure nf_conntrack or ip route cache is not killing you ?
>>>>
>>>> Filling 512 or 1024 RX ring on Gigabit link can be very fast, especially 
>>>> if ip route cache is full.
>>>>
>>>> rtstat -c10 -i1
>>> conntrack disabled, it is just enabled for second on load and then unloaded.
>> ok :)
>>
>>> MegaRouter-KARAM ~ # rtstat -c10 -i1
>>>
> rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|
>>>  entries|  in_hit|in_slow_|in_slow_|in_no_ro|  in_brd|in_marti|in_marti|
>>>
> out_hit|out_slow|out_slow|gc_total|gc_ignor|gc_goal_|gc_dst_o|in_hlist|out_hlis|
>>>         |        |     tot|      mc|     ute|        |  an_dst|  an_src|     
>>>   |    _tot|     _mc|        |      ed|    miss| verflow| _search|t_search|
>>>    63448|229209146|22225578|   13754|      12|    2822|       0|     104|  
>>> 54647|   27606|     570|21782075|21776859|      74|       0|215222374|  
> 61294|
>>>    66085|  141462|    5268|       8|       0|       4|       0|       0|     
>>>  4|       2|       0|    5274|    5274|       0|       0|  254424|      10|
>>>    59947|  132660|   20570|       4|       0|       4|       0|       0|     
>>>  8|      14|       0|   20584|   20584|       0|       0|  185738|      24|
>>>    56995|  132416|   16918|      12|       0|       2|       0|       0|     
>>>  6|       4|       0|   16932|   16932|       0|       0|   68378|       8|
>>>    56422|  137058|   12336|       8|       0|       0|       0|       0|     
>>>  8|       2|       0|   12344|   12344|       0|       0|   84022|       4|
>>>    56819|  140526|    9896|      10|       0|       0|       0|       0|     
>>>  6|       0|       0|    9898|    9896|       0|       0|   99138|       4|
>>>    57580|  136936|    8370|      10|       0|       2|       0|       0|     
>>>  8|       6|       2|    8378|    8378|       0|       0|  110834|      22|
>>>    51583|  120138|   26828|      20|       0|       0|       0|       0|     
>>>  4|       8|       0|   26848|   26848|       0|       0|   99292|      24|
>>>    49354|  128076|   21606|      14|       0|       2|       0|       0|     
>>>  0|      10|       0|   21626|   21626|       0|       0|   60546|      12|
>>>
>>>
>>>
>> Hum... typical IP route cache congestion ?
>>
>> echo 1 >/proc/sys/net/ipv4/route/gc_interval
>> echo 2 >/proc/sys/net/ipv4/route/gc_elasticity
> Doesn't help, nothing changed.

Your change on gc_interval can be delayed up to 60 seconds, you need to be patient :)

> 
>> You might want to boot with rhash_entries=131071 to play with IP 
>> route cache size, but I am not sure your workload can fit.
> I will try it, but thats kind of difficult, i cannot reboot anymore near 30
> minutes.

Before rebooting, make sure you can oprofile your kernel, this is the next step :)

Also, try to cpu affine both eth1 interrupts and timer interrupts (same cpu handling both)