linux/include
Eric Dumazet ffe4ccd359 net: add net.core.qdisc_max_burst
In blamed commit, I added a check against the temporary queue
built in __dev_xmit_skb(). Idea was to drop packets early,
before any spinlock was acquired.

if (unlikely(defer_count > READ_ONCE(q->limit))) {
	kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP);
	return NET_XMIT_DROP;
}

It turned out that HTB Qdisc has a zero q->limit.
HTB limits packets on a per-class basis.
Some of our tests became flaky.

Add a new sysctl : net.core.qdisc_max_burst to control
how many packets can be stored in the temporary lockless queue.

Also add a new QDISC_BURST_DROP drop reason to better diagnose
future issues.

Thanks Neal !

Fixes: 100dfa74ca ("net: dev_queue_xmit() llist adoption")
Reported-and-bisected-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20260107104159.3669285-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-13 10:12:11 +01:00
..
acpi
asm-generic hyperv-next for v6.19 2025-12-09 06:10:17 +09:00
clocksource clocksource/drivers/arm_arch_timer_mmio: Switch over to standalone driver 2025-09-23 12:31:50 +02:00
crypto This update includes the following changes: 2025-12-03 11:28:38 -08:00
cxl
drm drm/pagemap, drm/xe: Ensure that the devmem allocation is idle before use 2025-12-23 10:11:59 +01:00
dt-bindings This pull request is entirely SoC clk drivers, not for lack of trying to modify 2025-12-08 09:38:52 +09:00
hyperv mshv: Add definitions for MSHV sleep state configuration 2025-12-05 23:24:57 +00:00
keys
kunit kunit: Enforce task execution in {soft,hard}irq contexts 2025-12-22 12:20:08 -08:00
kvm
linux net: airoha: Fix typo in airoha_ppe_setup_tc_block_cb definition 2026-01-12 19:17:24 -08:00
math-emu
media media: v4l2-isp: Rename block_info to block_type_info 2025-11-14 15:48:49 +01:00
memory
misc
net net: add net.core.qdisc_max_burst 2026-01-13 10:12:11 +01:00
pcmcia
ras Significant patch series in this merge are as follows: 2025-12-05 13:52:43 -08:00
rdma RDMA/core: Add new IB rate for XDR (8x) support 2025-11-24 02:58:30 -05:00
rv rv: Fix compilation if !CONFIG_RV_REACTORS 2025-12-02 12:33:37 -05:00
scsi Merge branch 6.18/scsi-fixes into 6.19/scsi-staging 2025-11-19 22:59:25 -05:00
soc This pull request is entirely SoC clk drivers, not for lack of trying to modify 2025-12-08 09:38:52 +09:00
sound ASoC: soc-acpi / SOF: Add best_effort flag to get_function_tplg_files op 2025-12-15 23:08:35 +09:00
target Merge patch series "target: RW/num_cmds stats improvements" 2025-11-02 22:07:27 -05:00
trace nfsd-6.19 fixes: 2026-01-06 09:12:52 -08:00
uapi nfsd-6.19 fixes: 2026-01-06 09:12:52 -08:00
ufs Merge patch series "Add OP-TEE based RPMB driver for UFS devices" 2025-11-20 10:26:13 -05:00
vdso Updates for the VDSO subsystem: 2025-09-30 16:58:21 -07:00
video drm/vesadrm: Support DRM_FORMAT_C8 2025-08-26 09:54:20 +02:00
xen
Kbuild