[v5,iwl-net,0/3] ice: fix Rx data path for heavy 9k MTU traffic

Message

Maciej Fijalkowski Jan. 23, 2025, 3:01 p.m. UTC

v4->v5:
* add missing kdoc variable description in patch 3 (Simon Horman)
* include review tags from Simon

v3->v4:
* fix kdoc issues (Simon Horman)
* fix typo in commit msg in patch 1 (Simon Horman)

v2->v3:
* s/intel/iwl in patch subjects (Jakub Kicinski)

v1->v2:
* pass ntc to ice_put_rx_mbuf() (pointed out by Petr Oros) in patch 1
* add review tags from Przemek Kitszel (thanks!)
* make sure patches compile and work ;)


Hello in 2025,

this patchset fixes a pretty nasty issue that was reported by RedHat
folks which occured after ~30 minutes (this value varied, just trying
here to state that it was not observed immediately but rather after a
considerable longer amount of time) when ice driver was tortured with
jumbo frames via mix of iperf traffic executed simultaneously with
wrk/nginx on client/server sides (HTTP and TCP workloads basically).

The reported splats were spanning across all the bad things that can
happen to the state of page - refcount underflow, use-after-free, etc.
One of these looked as follows:

[ 2084.019891] BUG: Bad page state in process swapper/34  pfn:97fcd0
[ 2084.025990] page:00000000a60ee772 refcount:-1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x97fcd0
[ 2084.035462] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
[ 2084.041990] raw: 0017ffffc0000000 dead000000000100 dead000000000122 0000000000000000
[ 2084.049730] raw: 0000000000000000 0000000000000000 ffffffffffffffff 0000000000000000
[ 2084.057468] page dumped because: nonzero _refcount
[ 2084.062260] Modules linked in: bonding tls sunrpc intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common i10nm_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm mgag200 irqd
[ 2084.137829] CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Not tainted 5.14.0-427.37.1.el9_4.x86_64 #1
[ 2084.147039] Hardware name: Dell Inc. PowerEdge R750/0216NK, BIOS 1.13.2 12/19/2023
[ 2084.154604] Call Trace:
[ 2084.157058]  <IRQ>
[ 2084.159080]  dump_stack_lvl+0x34/0x48
[ 2084.162752]  bad_page.cold+0x63/0x94
[ 2084.166333]  check_new_pages+0xb3/0xe0
[ 2084.170083]  rmqueue_bulk+0x2d2/0x9e0
[ 2084.173749]  ? ktime_get+0x35/0xa0
[ 2084.177159]  rmqueue_pcplist+0x13b/0x210
[ 2084.181081]  rmqueue+0x7d3/0xd40
[ 2084.184316]  ? xas_load+0x9/0xa0
[ 2084.187547]  ? xas_find+0x183/0x1d0
[ 2084.191041]  ? xa_find_after+0xd0/0x130
[ 2084.194879]  ? intel_iommu_iotlb_sync_map+0x89/0xe0
[ 2084.199759]  get_page_from_freelist+0x11f/0x530
[ 2084.204291]  __alloc_pages+0xf2/0x250
[ 2084.207958]  ice_alloc_rx_bufs+0xcc/0x1c0 [ice]
[ 2084.212543]  ice_clean_rx_irq+0x631/0xa20 [ice]
[ 2084.217111]  ice_napi_poll+0xdf/0x2a0 [ice]
[ 2084.221330]  __napi_poll+0x27/0x170
[ 2084.224824]  net_rx_action+0x233/0x2f0
[ 2084.228575]  __do_softirq+0xc7/0x2ac
[ 2084.232155]  __irq_exit_rcu+0xa1/0xc0
[ 2084.235821]  common_interrupt+0x80/0xa0
[ 2084.239662]  </IRQ>
[ 2084.241768]  <TASK>

The fix is mostly about reverting what was done in commit 1dc1a7e7f410
("ice: Centrallize Rx buffer recycling") followed by proper timing on
page_count() storage and then removing the ice_rx_buf::act related logic
(which was mostly introduced for purposes from cited commit).

Special thanks to Xu Du for providing reproducer and Jacob Keller for
initial extensive analysis.

Thanks,
Maciej


Maciej Fijalkowski (3):
  ice: put Rx buffers after being done with current frame
  ice: gather page_count()'s of each frag right before XDP prog call
  ice: stop storing XDP verdict within ice_rx_buf

 drivers/net/ethernet/intel/ice/ice_txrx.c     | 150 ++++++++++++------
 drivers/net/ethernet/intel/ice/ice_txrx.h     |   1 -
 drivers/net/ethernet/intel/ice/ice_txrx_lib.h |  43 -----
 3 files changed, 103 insertions(+), 91 deletions(-)