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b=o6S03N2Vb6Bnya0M0gTxZaYmBO6u9oCKKJ+dC0bhcbRGf8da6XQ6ApMDwZ4GLuAnQ 5aEtaHfeHUspKMuG0lcvEka/YNh4kq05/9phbnoPipiZZlakLSQmzVE7mKlHfdq5ND oIE7xUyKv3f2UdOHmJgwfs2uTP0PlvQNPIirSOJe1nD9de147v1MekZ6gQhdJqOAks RKR07htrwmhV4FRaJLnY6ZaATv+ummWDutTSujcqeeXu0lsySnf5uYgywEybNOSSBT 6MNiJnTlWoAvKXF8algc0qFQ6mLt3u33zbsXd+8bGc3SkFKvKPlXCoe4H6UWzLWNC9 6sFEa1HPszzYg== Message-ID: Date: Thu, 14 May 2026 18:02:59 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [linux-next:master] [mm, slab] 298cdbf5f7: will-it-scale.per_process_ops 6.3% regression Content-Language: en-US From: "Vlastimil Babka (SUSE)" To: kernel test robot , "Harry Yoo (Oracle)" Cc: oe-lkp@lists.linux.dev, lkp@intel.com, Hao Li , linux-mm@kvack.org References: <202605112204.9382cecf-lkp@intel.com> <90bf195e-45fb-423c-b686-49be9cadbd11@kernel.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 135DE1C001A X-Rspam-User: X-Stat-Signature: ho4pg5pa6cc3us3dnkg3g7rtti4y6w6u X-HE-Tag: 1778774583-812212 X-HE-Meta: U2FsdGVkX18OZ+TdysIbP7noBrejWlC1kiKS68j+of2VGEnoO/8Ls7je+ilwXD7S/CYaXJ1wUEGY2SseceNUeKqLSDDi7p2gQPFj3v7QYfI8bZxCKOdeUoVDFBeTMotCrauukmvLhfE7mCf/5PyQX/4UuQQgwxrFcKUYzht/g/krPuhh7vAowKB1zalmAulE9mPvQqTDodXQBEv2JHWKJbjfd3CNqlIR57tg4lqkOaYc9QIOw0y5QXEUvxs7koM3goKEqbKSMeDZvdXfsTdYJs6bdrU1y4X6wW7KC19yG+vLn5z/ysZEZ3zx24squqmcylc8aMTEN7QNS9E32kp2MC7lpXBtYaEH0KyjajL/AOLaCRIGsaia+syeri/WOdecnyShSAs0teA574VwPsHVuXxvEgEO64vN3lcSY6lAt2AlQtxKItt0y8tu8gc2q+LRnOCY+15gza6ffuTtinuE8tPfmJopBWXOAdwOLvkblrONsORveH+HnDrpmtzlanmY0x/M8Inpm/RS0fsYLVAFiJKdeR7ee3h9eSU3hF5BABa++4Xd7JQL84k82ObHXp2YkPf5MNQ9PNyRq3QBgRRUDC6oRqrHRRUR81sDvFLxSgVfUY1RfZ8PT6tt5VCJbXutAevBxDJGxZd6PxwdCN4zAdgfxV4+s7JYMKi/zgSSIO9zku4io3B/m6YIvRpRrXnt+t35pBDzQLNdV3DGhEgaioEISLj+ePw+HLbfVW4ReYJAQi8+kvIYrPPmVFLyPoBRlg9c73I7odcbgYb/dBDX0Yn6gEH0L7LHcHXocgw6pAbI89lrpQut+oiROGlxtGfDDeJyNfQHgUrrVeYvwU8dL95LzcqPLM3Nmtd+Cw30nGURA3zyVoO8kQu39hIzCUG/8RKmygvumBEXftPJWEqyc09UQFjAPMLLJpgtwM46K0NSiBncASJEYb7vFRU6DzVRF+E3cAQU0PoFSX2XNUg v35+18qH 6a29tFbSWKVYJ6s0HamY95WRxHnBRYYZt67qFItBggUf0fDz3GLZzxAeUEbRQM7F7guG6TJP9amrF8bGsV+AmsZGDjGVb96zgV9WebYi5lSdzLVQ0IybDt3e4mmbhOsi/6aMVo2w0P/EP4J7N8o+7dRHY7LwlVzzRAWSkYVj/HKvBbCaE7+OXuBTC+j724SF2CpnhXxonPYOsRwbw1BRPHEFUbb6TGr9zTqyMXSMftErko1Ix2pATOv3P1byceLE9UMXkblvjHdn6tWWjSRJ/cay1SPc+53+ag9oZd8vCFJX+h2eaQsg/U1C0Ou+rX4QYUrvuGyaGq7pwu4g= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 5/14/26 18:00, Vlastimil Babka (SUSE) wrote: > On 5/14/26 16:45, Vlastimil Babka (SUSE) wrote: >> On 5/11/26 16:45, kernel test robot wrote: >>> >>> >>> Hello, >>> >>> kernel test robot noticed a 6.3% regression of will-it-scale.per_process_ops on: >> >> Yay for an optimization that was supposed to have no tradeoffs :) > > Does this help? I don't expect much, but perhaps... And a separate measurement with this on top of the previous one, plase? It's just that __slab_free() would have been adding to tail so let's try it too. >From 8fba1377797478a945d97ad6163021d95ac7665c Mon Sep 17 00:00:00 2001 From: "Vlastimil Babka (SUSE)" Date: Thu, 14 May 2026 18:00:52 +0200 Subject: [PATCH] mm, slab: ADD_TO_TAIL in __refill_objects_node --- mm/slub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 0cc6c88f11e3..35e574e94538 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -7193,7 +7193,7 @@ __refill_objects_node(struct kmem_cache *s, void **p, gfp_t gfp, unsigned int mi list_for_each_entry_safe(slab, slab2, &pc.slabs, slab_list) { list_del(&slab->slab_list); - add_partial(n, slab, ADD_TO_HEAD); + add_partial(n, slab, ADD_TO_TAIL); } spin_unlock_irqrestore(&n->list_lock, flags); -- 2.54.0