netdev - [PATCH net-next 0/3] net: netpoll: Improve SKB pool management

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Message-ID: <20241025142025.3558051-1-leitao@debian.org>
Date: Fri, 25 Oct 2024 07:20:17 -0700
From: Breno Leitao <leitao@...ian.org>
To: kuba@...nel.org,
	horms@...nel.org,
	davem@...emloft.net,
	edumazet@...gle.com,
	pabeni@...hat.com
Cc: thepacketgeek@...il.com,
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	aehkn@...hub.one
Subject: [PATCH net-next 0/3] net: netpoll: Improve SKB pool management

The netpoll subsystem pre-allocates 32 SKBs in a pool for emergency use
during out-of-memory conditions. However, the current implementation has
several inefficiencies:

 * The SKB pool, once allocated, is never freed:
	 * Resources remain allocated even after netpoll users are removed
	 * Failed initialization can leave pool populated forever
 * The global pool design makes resource tracking difficult

This series addresses these issues through three patches:


Patch 1 ("net: netpoll: Defer skb_pool population until setup success"):
 - Defer SKB pool population until setup validation passes

Patch 2 ("net: netpoll: Individualize the skb pool"):
 - Replace global pool with per-user pools in netpoll struct

Patch 3 ("net: netpoll: flush skb pool during cleanup"):
- Properly free pool resources during netconsole cleanup

These changes improve resource management and make the code more
maintainable.  As a side benefit, the improved structure would allow
netpoll to be modularized if desired in the future.

What is coming next?

Once this patch is integrated, I am planning to have the SKBs being
refilled outside of hot (send) path, in a work thread.

Breno Leitao (3):
  net: netpoll: Defer skb_pool population until setup success
  net: netpoll: Individualize the skb pool
  net: netpoll: flush skb pool during cleanup

 include/linux/netpoll.h |  1 +
 net/core/netpoll.c      | 52 +++++++++++++++++++++++++----------------
 2 files changed, 33 insertions(+), 20 deletions(-)

-- 
2.43.5