On 10/8/25 12:10, Thomas Monjalon wrote:
08/10/2025 10:38, Bruce Richardson:
On Mon, Oct 06, 2025 at 03:02:57PM +0200, Thierry Herbelot wrote:
The e1000 PMD stopped working under Ubuntu-24.04 (using gcc-13) when
compiled with -O3 (default level for all DPDK code). There is a crash
when starting testpmd:
(gdb) bt
#0 rte_read32_relaxed (addr=0x1100800e00) at
../sources/lib/eal/include/generic/rte_io.h:290
#1 rte_read32 (addr=0x1100800e00) at
../sources/lib/eal/include/generic/rte_io.h:345
#2 e1000_read_addr (addr=0x1100800e00) at
../sources/drivers/net/intel/e1000/base/e1000_osdep.h:106
#3 e1000_id_led_init_generic (hw=0x1586788c0) at
../sources/drivers/net/intel/e1000/base/e1000_mac.c:1844
#4 0x000062aaf653c85f in e1000_init_hw_82540 (hw=0x1586788c0)
at ../sources/drivers/net/intel/e1000/base/e1000_82540.c:308
#5 0x000062aaf6db8227 in em_hardware_init (hw=hw@entry=0x1586788c0)
at ../sources/drivers/net/intel/e1000/em_ethdev.c:920
#6 0x000062aaf65340ff in em_hw_init (hw=0x1586788c0) at
../sources/drivers/net/intel/e1000/em_ethdev.c:445
#7 eth_em_dev_init (eth_dev=eth_dev@entry=0x62aaff346000 <rte_eth_devices>)
at ../sources/drivers/net/intel/e1000/em_ethdev.c:314
#8 0x000062aaf6db8b71 in rte_eth_dev_pci_generic_probe
(private_data_size=11240,
dev_init=0x62aaf6db8310 <eth_em_dev_init>, pci_dev=0x62ab2853dd90) at
../sources/lib/ethdev/ethdev_pci.h:150
#9 eth_em_pci_probe (pci_drv=<optimized out>, pci_dev=0x62ab2853dd90)
at ../sources/drivers/net/intel/e1000/em_ethdev.c:365
#10 0x000062aaf646adf5 in rte_pci_probe_one_driver (dr=dr@entry=0x62aaf82d8020
<rte_em_pmd>,
dev=dev@entry=0x62ab2853dd90) at
../sources/drivers/bus/pci/pci_common.c:299
#11 0x000062aaf6a15f7d in pci_probe_all_drivers (dev=0x62ab2853dd90) at
../sources/drivers/bus/pci/pci_common.c:383
#12 pci_probe () at ../sources/drivers/bus/pci/pci_common.c:410
#13 0x000062aaf7a485f3 in rte_bus_probe () at
../sources/lib/eal/common/eal_common_bus.c:84
#14 0x000062aaf670585d in rte_eal_init (argc=argc@entry=146,
argv=argv@entry=0x7fffca468898)
at ../sources/lib/eal/linux/eal.c:1253
The crash is linked to the use of gcc-13: under Ubuntu-24.04 testpmd
compiled with gcc-11 from the same DPDK tree works as expected.
The perfect solution would be for someone to investigate why the
PMD crashes. However, this depends on Maintainer availability.
A less-perfect solution is to reduce the optimization level
(like another proposal for net/qede: see Link).
Thanks for reporting the issue. I'd like to spend a little time trying to
really root cause the issue before applying this workaround patch. Can you
provide a bit more info about the setup you used when you hit this issue. I
expect a lot of use of e1000 driver is in virtualized setups, but can you
confirm if that was the case here, or were you using real hardware?
Hello Bruce, Thomas
Sorry for the missing info: the issue was indeed seen in qemu (in more
than one version).
I'm not sure we have a real NIC lying around, for this PMD.
If we do have to apply this workaround fix of reducing optimization level,
I see you reduce optimization for both the base code and the DPDK-specific
driver code. Is it necessary to reduce optimization on both, or can we get
away with just reducing it on the DPDK part alone?
As for net/qede, I did not take time to investigate which piece of code
was concerned. I just checked that testpmd really works in an
Ubuntu-24.04 VM, when DPDK is compiled with gcc-11 rather than the
default gcc-13.
Then the crude workaround is to drop the optimization level for all of
the PMD. As for net/qede, '-O1' is a compromise as the PMD seems to be
working fine, and still the performance is acceptable.
We are not sure the workaround will work with every compilers to come.
Of course it is better to fix the root cause.
Agreed !
Would it be possible to have a list of the PMDs which are known to be
currently being tested (for example e810, i40e for Intel) ? (and then
the list of PMDs which are "under lighter monitoring")
Best regards
Thierry
If we cannot fix it in time, we can add this workaround in the release notes.
But please, let's not apply it in the codebase.
--
Thierry Herbelot
