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To: Eric Dumazet Cc: "David S. Miller" , Jakub Kicinski , Paolo Abeni , Neal Cardwell , David Ahern , Simon Horman , Kuniyuki Iwashima , netdev@vger.kernel.org, Kuniyuki Iwashima Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, Aug 20, 2025 at 11:46=E2=80=AFPM Eric Dumazet = wrote: > > On Wed, Aug 20, 2025 at 11:16=E2=80=AFPM Kuniyuki Iwashima wrote: > > > > From: Kuniyuki Iwashima > > > > __module_get() in inet_twsk_alloc() was necessary to prevent > > unloading tw->tw_prot, which is used in inet_twsk_free(). > > > > DCCP has gone, and TCP is built-in, so the pair is no longer needed. > > > > ULPs also do not need it because > > > > * kTLS and XFRM_ESPINTCP restore sk_prot before close() > > * MPTCP is built-in > > * SMC uses TCP as is > > > > , but using tw_prot without module_get() would be error prone to > > future ULP addition. > > > > Now we can use kfree() without the slab cache pointer thanks to SLUB. > > Right, but kmem_cache_free() has extra debug checks (SLAB_CONSISTENCY_CHE= CKS): > we check the object was indeed allocated from a precise cache. > > I would prefer leaving this in place. > > Such a conversion could be done globally if you think about it, no > need for hundreds of patches. > > static inline void kmem_cache_free(struct kmem_cache *s, void *x) > { > kfree(x); > } > > > > > > Let's use kfree() in inet_twsk_free() and remove 2 atomic ops > > for each connection. > > > > Where are you seeing the atomic ops exactly ? > > TCP is builtin, so .owner is NULL. Ah exactly, I think I was confused with DCCP. I'll drop this patch in v2. Thanks!