Re: [PATCH] net: Revert tx queue length on partial failure in dev_qdisc_change_tx_queue_len()
From: Eric Dumazet <edumazet@google.com>
Date: 2025-07-23 18:36:43
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linux-kernel-mentees, lkml
On Wed, Jul 23, 2025 at 11:17 AM Suchit K [off-list ref] wrote:
quoted
WRITE_ONCE() is missing.quoted
+ while (i >= 0) { + qdisc_change_tx_queue_len(dev, &dev->_tx[i]);What happens if one of these calls fails ? I think a fix will be more complicated...Hi Eric, Given that pfifo_fast_change_tx_queue_len is currently the only implementation of change_tx_queue_len, would it be reasonable to handle partial failures solely within pfifo_fast_change_tx_queue_len (which in turn leads to skb_array_resize_multiple_bh)? In other words, is it sufficient to modify only the underlying low level implementation of pfifo_fast_change_tx_queue_len for partial failures, given that it's the sole implementation of change_tx_queue_len?
A generic solution will involve two phases... Lots of core changes, for a very narrow case. Most of us do not use pfifo_fast anyway.