[PATCH v2 0/2] wifi: ath12k: isolate RXDMA page-fragment caches

[Nikolai Semendiaev]

Hi,

This series adapts Mark Ruvald Pedersen's ath11k page-fragment cache
changes to ath12k. On QCN9274, sustained WAN traffic
can exhaust memory when Ethernet and Wi-Fi run on the same CPU.
Long-lived RXDMA buffers share per-CPU page-fragment caches with other
network users and can pin mostly unused 32-KiB backing pages.

Patch 1 makes external IRQ transitions follow the NAPI state so that
crash recovery can safely quiesce RXDMA before teardown. Patch 2 gives
regular and monitor RXDMA rings private caches and drains them after
their buffers have been released. It also fixes alignment of empty
skbs and preserves monitor status buffer capacity after alignment.

The series is based on ath.git main at:
388d3c42e8aba1cfc3c6d2c52877a46d8cf740db (Linux 7.3-rc5).
Runtime measurements were made on Linux 6.18.54, with Ethernet and
Wi-Fi IRQs on CPU0:

  Hardware: QCN9274 hw2.0 PCI
  Firmware: WLAN.WBE.1.6-01243-QCAHKSWPL_SILICONZ-1

Two 45-second downloads showed peak order-3 memory growth of 54 and
68 MiB. An earlier unpatched 45-second test grew by 187 MiB, and longer
unpatched downloads reached OOM.

A five-minute download at about 660 Mbps transferred 24.8 GB without
OOM. Peak growth was 105 MiB, falling to 35 MiB above baseline after
one minute idle.

Thanks,
Nikolai

Changes in v2:
- Include linux/bug.h before linux/page_frag_cache.h in dp.c to make
  WARN_ON_ONCE available on Alpha. This fixes the build error reported
  by the kernel test robot:
  https://lore.kernel.org/oe-kbuild-all/202610072103.1v2wWX3z-lkp@intel.com/

Nikolai Semendiaev (2):
  wifi: ath12k: make external IRQ control idempotent
  wifi: ath12k: use private page-frag caches for RXDMA rings

 drivers/net/wireless/ath/ath12k/ahb.c    |  4 +--
 drivers/net/wireless/ath/ath12k/core.c   |  3 ++
 drivers/net/wireless/ath/ath12k/dp.c     |  4 +++
 drivers/net/wireless/ath/ath12k/dp.h     |  3 ++
 drivers/net/wireless/ath/ath12k/dp_mon.c | 29 +++++++++------
 drivers/net/wireless/ath/ath12k/dp_rx.c  | 45 +++++++++++++++++++++---
 drivers/net/wireless/ath/ath12k/dp_rx.h  |  2 ++
 drivers/net/wireless/ath/ath12k/pci.c    |  6 ++--
 8 files changed, 74 insertions(+), 22 deletions(-)


base-commit: 388d3c42e8aba1cfc3c6d2c52877a46d8cf740db
-- 
2.43.0