On 06/20/2014 07:20 AM, Stefan Baranoff wrote: > All, > > We are seeing 'random' memory corruption in mbufs coming from the ixgbe UIO > driver and I am looking for some pointers on debugging it. Our software was > running flawlessly for weeks at a time on our old Westmere systems (CentOS > 6.4) but since moving to a new Sandy Bridge v2 server (also CentOS 6.4) it > runs for 1-2 minutes and then at least one mbuf is overwritten with > arbitrary data (pointers/lengths/RSS value/num segs/etc. are all > ridiculous). Both servers are using the 82599EB chipset (x520) and the DPDK > version (1.6.0r2) is identical. We recently also tested on a third server > running RHEL 6.4 with the same hardware as the failing Sandy Bridge based > system and it is fine (days of runtime no failures). > > Running all of this in GDB with 'record' enabled and setting a watchpoint > on the address which contains the corrupted data and executing a > 'reverse-continue' never hits the watchpoint [GDB newbie here -- assuming > 'watch *(uint64_t*)0x7FB.....' should work]. My first thought was memory > corruption but the BIOS memcheck on the ECC RAM shows no issues. > > Also looking at mbuf->pkt.data, as an example, the corrupt value was the > same 6/12 trials but I could not find that value elsewhere in the processes > memory. This doesn't seem "random" and points to a software bug but I > cannot for the life of me get GDB to tell me where the program is when that > memory is written to. Incidentally trying this with the PCAP driver and > --no-huge to run valgrind shows no memory access errors/uninitialized > values/etc. > > Thoughts? Pointers? Ways to rule in/out hardware other than going 1 by 1 > removing each of the 24 DIMMs? > > Thanks so much in advance! > Stefan Run memtest to rule out bad ram.
Pb
