From: "Christoph Lameter (Ampere)" <cl@gentwo.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Hao Li <hao.li@linux.dev>, Harry Yoo <harry.yoo@oracle.com>,
Petr Tesarik <ptesarik@suse.com>,
David Rientjes <rientjes@google.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Suren Baghdasaryan <surenb@google.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Alexei Starovoitov <ast@kernel.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev, bpf@vger.kernel.org,
kasan-dev@googlegroups.com,
kernel test robot <oliver.sang@intel.com>,
stable@vger.kernel.org, "Paul E. McKenney" <paulmck@kernel.org>
Subject: Re: [PATCH v4 00/22] slab: replace cpu (partial) slabs with sheaves
Date: Wed, 4 Feb 2026 10:24:46 -0800 (PST) [thread overview]
Message-ID: <2abde505-1e35-8d74-2806-7a3cd430e306@gentwo.org> (raw)
In-Reply-To: <665ff739-73d8-4996-95e0-f09c3e5b6552@suse.cz>
On Wed, 4 Feb 2026, Vlastimil Babka wrote:
> > So I think the performance of the percpu partial list and the sheaves mechanism
> > is roughly the same, which is consistent with our expectations.
>
> Thanks!
There are other considerations that usually do not show up well in
benchmark tests.
The sheaves cannot do the spatial optimizations that cpu partial lists
provide. Fragmentation in slab caches (and therefore the nubmer of
partial slab pages) will increase since
1. The objects are not immediately returned to their slab pages but end up
in some queuing structure.
2. Available objects from a single slab page are not allocated in sequence
to empty partial pages and remove the page from the partial lists.
Objects are put into some queue on free and are processed on a FIFO basis.
Objects allocated may come from lots of different slab pages potentially
increasing TLB pressure.
next prev parent reply other threads:[~2026-02-04 18:24 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-23 6:52 Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 01/22] mm/slab: add rcu_barrier() to kvfree_rcu_barrier_on_cache() Vlastimil Babka
2026-01-27 16:08 ` Liam R. Howlett
2026-01-23 6:52 ` [PATCH v4 02/22] mm/slab: fix false lockdep warning in __kfree_rcu_sheaf() Vlastimil Babka
2026-01-23 12:03 ` Sebastian Andrzej Siewior
2026-01-24 10:58 ` Harry Yoo
2026-01-23 6:52 ` [PATCH v4 03/22] slab: add SLAB_CONSISTENCY_CHECKS to SLAB_NEVER_MERGE Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 04/22] mm/slab: move and refactor __kmem_cache_alias() Vlastimil Babka
2026-01-27 16:17 ` Liam R. Howlett
2026-01-27 16:59 ` Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 05/22] mm/slab: make caches with sheaves mergeable Vlastimil Babka
2026-01-27 16:23 ` Liam R. Howlett
2026-01-23 6:52 ` [PATCH v4 06/22] slab: add sheaves to most caches Vlastimil Babka
2026-01-26 6:36 ` Hao Li
2026-01-26 8:39 ` Vlastimil Babka
2026-01-26 13:59 ` Breno Leitao
2026-01-27 16:34 ` Liam R. Howlett
2026-01-27 17:01 ` Vlastimil Babka
2026-01-29 7:24 ` Zhao Liu
2026-01-29 8:21 ` Vlastimil Babka
2026-01-30 7:15 ` Zhao Liu
2026-02-04 18:01 ` Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 07/22] slab: introduce percpu sheaves bootstrap Vlastimil Babka
2026-01-26 6:13 ` Hao Li
2026-01-26 8:42 ` Vlastimil Babka
2026-01-27 17:31 ` Liam R. Howlett
2026-01-23 6:52 ` [PATCH v4 08/22] slab: make percpu sheaves compatible with kmalloc_nolock()/kfree_nolock() Vlastimil Babka
2026-01-23 18:05 ` Alexei Starovoitov
2026-01-27 17:36 ` Liam R. Howlett
2026-01-29 8:25 ` Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 09/22] slab: handle kmalloc sheaves bootstrap Vlastimil Babka
2026-01-27 18:30 ` Liam R. Howlett
2026-01-23 6:52 ` [PATCH v4 10/22] slab: add optimized sheaf refill from partial list Vlastimil Babka
2026-01-26 7:12 ` Hao Li
2026-01-29 7:43 ` Harry Yoo
2026-01-29 8:29 ` Vlastimil Babka
2026-01-27 20:05 ` Liam R. Howlett
2026-01-29 8:01 ` Harry Yoo
2026-01-23 6:52 ` [PATCH v4 11/22] slab: remove cpu (partial) slabs usage from allocation paths Vlastimil Babka
2026-01-23 18:17 ` Alexei Starovoitov
2026-01-23 6:52 ` [PATCH v4 12/22] slab: remove SLUB_CPU_PARTIAL Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 13/22] slab: remove the do_slab_free() fastpath Vlastimil Babka
2026-01-23 18:15 ` Alexei Starovoitov
2026-01-23 6:52 ` [PATCH v4 14/22] slab: remove defer_deactivate_slab() Vlastimil Babka
2026-01-23 17:31 ` Alexei Starovoitov
2026-01-23 6:52 ` [PATCH v4 15/22] slab: simplify kmalloc_nolock() Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 16/22] slab: remove struct kmem_cache_cpu Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 17/22] slab: remove unused PREEMPT_RT specific macros Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 18/22] slab: refill sheaves from all nodes Vlastimil Babka
2026-01-27 14:28 ` Mateusz Guzik
2026-01-27 22:04 ` Vlastimil Babka
2026-01-29 9:16 ` Harry Yoo
2026-01-23 6:52 ` [PATCH v4 19/22] slab: update overview comments Vlastimil Babka
2026-01-23 6:52 ` [PATCH v4 20/22] slab: remove frozen slab checks from __slab_free() Vlastimil Babka
2026-01-29 7:16 ` Harry Yoo
2026-01-23 6:52 ` [PATCH v4 21/22] mm/slub: remove DEACTIVATE_TO_* stat items Vlastimil Babka
2026-01-29 7:21 ` Harry Yoo
2026-01-23 6:53 ` [PATCH v4 22/22] mm/slub: cleanup and repurpose some " Vlastimil Babka
2026-01-29 7:40 ` Harry Yoo
2026-01-29 15:18 ` [PATCH v4 00/22] slab: replace cpu (partial) slabs with sheaves Hao Li
2026-01-29 15:28 ` Vlastimil Babka
2026-01-29 16:06 ` Hao Li
2026-01-29 16:44 ` Liam R. Howlett
2026-01-30 4:38 ` Hao Li
2026-01-30 4:50 ` Hao Li
2026-01-30 6:17 ` Hao Li
2026-02-04 18:02 ` Vlastimil Babka
2026-02-04 18:24 ` Christoph Lameter (Ampere) [this message]
2026-02-06 16:44 ` Vlastimil Babka
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