mbox series

[net-next,v3,0/2] net: netpoll: Improve SKB pool management

Message ID 20241114-skb_buffers_v2-v3-0-9be9f52a8b69@debian.org (mailing list archive)
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Series net: netpoll: Improve SKB pool management | expand

Message

Breno Leitao Nov. 14, 2024, 11 a.m. UTC
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: Individualize the skb pool"):
 - Replace global pool with per-user pools in netpoll struct

Patch 2 ("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.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
Changelog:
v3:
 * Use the skb_queue_purge_reason() helper instead of dropping the skb
   pool manually. (Jakub)

v2:
 * Drop the very first patch from v1 ("net: netpoll: Defer skb_pool
   population until setup success") (Jakub)
 * Move skb_queue_head_init() to the first patch, where it belongs to
   (Jakub)
 * https://lore.kernel.org/all/20241107-skb_buffers_v2-v2-0-288c6264ba4f@debian.org/

v1:
 * https://lore.kernel.org/all/20241025142025.3558051-1-leitao@debian.org/

- Link to v2: https://lore.kernel.org/r/20241107-skb_buffers_v2-v2-0-288c6264ba4f@debian.org

---
Breno Leitao (2):
      net: netpoll: Individualize the skb pool
      net: netpoll: flush skb pool during cleanup

 include/linux/netpoll.h |  1 +
 net/core/netpoll.c      | 45 ++++++++++++++++++++++++++-------------------
 2 files changed, 27 insertions(+), 19 deletions(-)
---
base-commit: a71c69f51d1119db5f7812b35f16e8ef7786b3f2
change-id: 20241107-skb_buffers_v2-f3e626100eda

Best regards,

Comments

patchwork-bot+netdevbpf@kernel.org Nov. 16, 2024, 2 a.m. UTC | #1
Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 14 Nov 2024 03:00:10 -0800 you wrote:
> 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
> 
> [...]

Here is the summary with links:
  - [net-next,v3,1/2] net: netpoll: Individualize the skb pool
    https://git.kernel.org/netdev/net-next/c/221a9c1df790
  - [net-next,v3,2/2] net: netpoll: flush skb pool during cleanup
    https://git.kernel.org/netdev/net-next/c/6c59f16f1770

You are awesome, thank you!