its failing at data_kva address because this is where I'm getting the kernel paging request fail BUG: unable to handle kernel paging request at 000007529d212900 and this is what my debug shows kva data addresses: data_kva 000007529d212900, kva->buff_add 00007f529d212880, kva->data_off 128, kni->mbuf_va (null), and kni->mbuf_kva ffff880000000000
I'm not sure how to verify that these are normal On Mon, Feb 27, 2017 at 4:41 PM, Wiles, Keith <[email protected]> wrote: > > > On Feb 27, 2017, at 4:22 PM, Sushil Adhikari <[email protected]> > wrote: > > > > I narrowed it to location where it was failing, its coming from > http://dpdk.org/browse/dpdk-stable/tree/lib/librte_eal/ > linuxapp/kni/kni_net.c?h=v16.07.2 line 169, I am getting the value of len > to be 1358 from len=kva->pkt_len; which seems right for ip packet and the > memory allocation from line 157 also seems to be working fine. when I print > the sizeof(*skb) or sizeof(struct sk_buff) its giving me 208, I guess I > dont know whether it should be the size we allocate from line 157, which is > len + 2 = 1360 or its fixed size structure of 208 byte. I would appreciate > any insight. > > Linux version 4.4.20 (sushila@dev03) (gcc version 4.9.2 (crosstool-NG > 1.20.0) ) #1 SMP Fri Feb 24 14:32:28 CST 2017 > > Looks like we need to determine which address is failing the skb_put() or > data_kva address. If the address that fails is at the end of the skb_put() > then I would think the len is wrong, meaning we are stepping on memory just > passed a page for the skb. If the address that fails is in the data_kva > then the calculations for that address are wrong in line 154. You may want > to printout the kva->data_off, buf_addr, mbuf_va and mbuf_kva to verify > these values seem normal. The data_off value should be reasonable (I guess) > meaning with a 2K range. > > Also print out the two values skb_put() and data_kva. You can use gdb to > example the memory using the dump memory command. (is it x/nn <address>) nn > is the read width, but you could leave off the ‘/nn’ for the default. > > > > > Thank you > > Sushil > > > > On Sat, Feb 25, 2017 at 10:31 AM, Wiles, Keith <[email protected]> > wrote: > > > > > On Feb 24, 2017, at 8:07 AM, Sushil Adhikari <[email protected]> > wrote: > > > > > > Resending because of unsupported email content type > > > > > > > > > yes hanging is the better word I guess, ctrl + c is not working to > actually stop the program. I also had display connected to the target > manchine and I have attached a picture that shows the messages in that > display that is where I saw "BUG:Unable to handle kernel paging request at > xxxxxx", which made me think that the program is in bad state. > > > > Sorry, I do not see why you are getting this message. All I can suggest > is to use GDB and see if you can determine why the message is happening. > > > > > > > > info thread in gdb shows one thread running > > > Id Target Id Frame > > > * 1 LWP 843 "dpdkKni" 0x000000000044eaee in rte_kni_tx_burst () > > > > > > On Thu, Feb 23, 2017 at 5:41 PM, Wiles, Keith <[email protected]> > wrote: > > > > > > > On Feb 23, 2017, at 2:38 PM, Sushil Adhikari <[email protected]> > wrote: > > > > > > > > While trying to run dpdk Kni application I ran in to a problem, with > > > > following error message > > > > BUG: unable to handle kernel paging request at 000007ffe2b92780 > > > > > > > > To run the application I first unbinded the ports from kernel module > and > > > > binded them to igb_uio > > > >> echo 0000:05:00.1 > /sys/bus/pci/drivers/ixgbe/unbind > > > >> echo 0000:05:00.0 > /sys/bus/pci/drivers/ixgbe/unbind > > > >> echo 0x8086 0x1528 > /sys/bus/pci/drivers/igb_uio/new_id > > > > > > > > I ran the application using gdb as > > > > > > > > [~]$ /root/gdb dpdkKni > > > > GNU gdb (crosstool-NG 1.20.0) 7.8 > > > > Copyright (C) 2014 Free Software Foundation, Inc. > > > > License GPLv3+: GNU GPL version 3 or later < > http://gnu.org/licenses/gpl.html > > > >> > > > > This is free software: you are free to change and redistribute it. > > > > There is NO WARRANTY, to the extent permitted by law. Type "show > copying" > > > > and "show warranty" for details. > > > > This GDB was configured as "x86_64-unknown-linux-gnu". > > > > Type "show configuration" for configuration details. > > > > For bug reporting instructions, please see: > > > > <http://www.gnu.org/software/gdb/bugs/>. > > > > Find the GDB manual and other documentation resources online at: > > > > <http://www.gnu.org/software/gdb/documentation/>. > > > > For help, type "help". > > > > Type "apropos word" to search for commands related to "word"... > > > > Reading symbols from dpdkKni...(no debugging symbols found)...done. > > > > (gdb) Run dpdkKni -c 0x0f -n 4 -- -P -p 0x3 > --config="(0,0,1),(1,2,3)" > > > > Starting program: /root/dpdkKni dpdkKni -c 0x0f -n 4 -- -P -p 0x3 > > > > --config="(0,0,1),(1,2,3)" > > > > warning: Could not load shared library symbols for linux-vdso.so.1. > > > > Do you need "set solib-search-path" or "set sysroot"? > > > > warning: Unable to find libthread_db matching inferior's thread > library, > > > > thread debugging will not be available. > > > > EAL: Detected 4 lcore(s) > > > > EAL: Probing VFIO support... > > > > EAL: PCI device 0000:05:00.0 on NUMA socket -1 > > > > EAL: probe driver: 8086:1528 net_ixgbe > > > > EAL: PCI device 0000:05:00.1 on NUMA socket -1 > > > > EAL: probe driver: 8086:1528 net_ixgbe > > > > Address of pktmbuf_pool 0x7ffff5a7dec0 > > > > APP: Initialising port 0 ... > > > > KNI: pci: 05:00:00 8086:1528 > > > > kni created for port 0 with kni[i] address 0x7fff75638280 with i 0 > > > > APP: Initialising port 1 ... > > > > KNI: pci: 05:00:01 8086:1528 > > > > kni created for port 1 with kni[i] address 0x7fff75629e00 with i 0 > > > > APP: Lcore 1 is writing to port 0 > > > > APP: Lcore 2 is reading from port 1 > > > > APP: Lcore 3 is writing to port 1 > > > > APP: Lcore 0 is reading from port 0 > > > > ^C > > > > Program received signal SIGINT, Interrupt. > > > > > > The program did not crash or get a segfault, but you hit control-c > which stopped the application. When you ran the application you started 4 > threads and this is why it would appear in different places when stopped. > > > > > > If the application is hanging then you can use control-C and then do > ‘info threads’ command to see the location of all threads. You can use the > ‘thread X’ command to switch between threads. Please check the command > usage here I am going from memory. > > > > > > I am not sure if the application has a -i option to get a command line > if so that maybe useful to enable, check the application to see if it used > cmdline feature. > > > > > > It maybe the application just sits running and you have to use other > tools or apps to send traffic on the KNI application, sorry I have not > really used the KNI example. > > > > > > > 0x000000000044e916 in rte_kni_tx_burst () > > > > (gdb) backtrace > > > > #0 0x000000000044e916 in rte_kni_tx_burst () > > > > #1 0x0000000000619758 in main_loop(void*) () > > > > #2 0x0000000000431183 in rte_eal_mp_remote_launch () > > > > #3 0x000000000040d312 in main () > > > > > > > > (this is where the program crashes) > > > > > > > > I tried to trace the crash with gdb(I am new to gdb) > > > > > > > > and when I do the backtrace it ends up in different functions each > time: > > > > this time it gave me rte_kni_tx_burst() > > > > > > > > I'm running latest dpdk version 17.02 and linux kernel is > > > > Linux version 4.4.20 (tcuser@cibuild08) (gcc version 4.9.2 > (crosstool-NG > > > > 1.20.0) ) #1 SMP > > > > > > > > I would appreciate any suggestion or insight regarding this issue. > > > > > > Regards, > > > Keith > > > > > > > > > <kni.jpg> > > > > Regards, > > Keith > > > > > > Regards, > Keith > >
