Le 05/08/2012 10:28, Eric Dumazet a écrit : > On Sun, 2012-08-05 at 10:16 +0200, LEROY christophe wrote: >> Le 02/08/2012 16:13, Eric Dumazet a écrit : >>> On Thu, 2012-08-02 at 14:27 +0200, leroy christophe wrote: >>>> Hi >>>> >>>> I'm having a big issue with UDP. Using a powerpc board (MPC860). >>>> >>>> With our board running kernel 2.4.17, I'm able to send 160000 voice >>>> packets (UDP, 96 bytes per packet) in 11 seconds. >>>> With the same board running either Kernel 2.6.35.14 or Kernel 3.4.7, I >>>> need 55 seconds to send the same amount of packets. >>>> >>>> >>>> Is there anything to tune in order to get same output rate as with >>>> Kernel 2.4 ? >>> kernel size is probably too big for your old / slow cpu. >>> >>> Maybe you added too many features on your 3.4.7 kernel. (netfilter ? >>> SLUB debugging ...) >>> >>> Its hard to say, 2.4.17 had less features and was faster. >>> >> Thanks for your answer. >> Yes I have netfilter as I need it. However, I tried without it and still >> need about 37 seconds to send the 160000 packets I was sending in 11 >> seconds with 2.4.17 >> >> I don't think there is any problem with size of the kernel. I still have >> plenty of memory available. >> > I believe you misunderstood me. > > I was referring to cpu caches ( dcache & icache ) > >> All debugging is turned off, and I'm not using SLUB but SLOB. >> I have 32Mbytes of RAM. Would SLUB be more performant than SLOB ? > I never used SLOB I cannot comment > > Please provide (on 3.4.7) > > cat /proc/cpuinfo > lsmod > dmesg > Ok, I have recompiled with SLUB. Find attached cpuinfo, lsmod and dmesg. I do not have any modules loaded.