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Miller" , Eric Dumazet , Jakub Kicinski , Simon Horman , Jason Xing , Kuniyuki Iwashima , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Kees Cook , linux-mm@kvack.org, Vlastimil Babka References: <20260702170728.168755-1-pfalcato@suse.de> <04debe19-bbe8-4b5f-9668-753d1f97832d@redhat.com> Content-Language: en-US From: Harry Yoo In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: CBC7C10000A X-Stat-Signature: 4yjxcgtffws4djq46ub8jef67zxehjyy X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1783517279-659592 X-HE-Meta: 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 WY3vDhVf Fi1SgCJHvxPlEDSSUAvWxUn+68M+xNFE0wyjyko2ujC4qx6UCRBzidhQJcPDFDXlbaG/7f3G0ypOtkmX5ZUOSVr59CDxMckysNHf8wvwjsOrb3unoG7qZhbLmFb7ZmKEGsC7RsAWj9/UkLHkOFnf0TkWvuYO8gha0szSebYEiUp8Zr/ctlmCGgrUuVBV/gqZCIYjw1djRzcMVe9WhlhUmylTWiWEnfb6vb8ZAJNiOvIsQiaVZYpGtUiCsQfQd16aGm7UlM1GN8WcXxvUwKR6xP6nFHiGLFVRt6tcbveViq0q5jW06Q3VBId8/k/vYTbBXK8k3 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/8/26 8:16 PM, Pedro Falcato wrote: > On Wed, Jul 08, 2026 at 10:30:50AM +0200, Paolo Abeni wrote: >> On 7/2/26 7:07 PM, Pedro Falcato wrote:> @@ -586,6 +586,8 @@ struct >> sk_buff *napi_build_skb(void *data, unsigned int frag_size) >>> } >>> EXPORT_SYMBOL(napi_build_skb); >>> >>> +static kmem_buckets *skb_data_buckets __ro_after_init; >>> + >>> static void *kmalloc_pfmemalloc(size_t obj_size, gfp_t flags, int node) >>> { >>> if (!gfp_pfmemalloc_allowed(flags)) >>> @@ -593,7 +595,8 @@ static void *kmalloc_pfmemalloc(size_t obj_size, gfp_t flags, int node) >>> if (!obj_size) >>> return kmem_cache_alloc_node(net_hotdata.skb_small_head_cache, >>> flags, node); >>> - return kmalloc_node_track_caller(obj_size, flags, node); >>> + return kmem_buckets_alloc_node_track_caller(skb_data_buckets, obj_size, >>> + flags, node); >> >> Sashiko noted that some drivers may require GFP_DMA buckets, and the >> above may break them: >> >> https://sashiko.dev/#/patchset/20260702170728.168755-1-pfalcato%40suse.de > > Oh, this is really awkward. Adding linux-mm and slab maintainers for input here. > > Considering the current slab bucketing does not seem to duplicate DMA or > CGROUP caches, could it make sense to duplicate those as well? Could we specify what kmalloc types the user needs when creating kmem_buckets and duplicate caches for the requested kmalloc types only? > Otherwise we could add a branch like: > > if (gfp_flags & __GFP_DMA) > /* use the global dma kmalloc caches */ -- Cheers, Harry / Hyeonggon