From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH v2 23/33] mm/memcg: Convert slab objcgs from struct page to struct slab Date: Tue, 14 Dec 2021 15:43:07 +0100 Message-ID: References: <20211201181510.18784-1-vbabka@suse.cz> <20211201181510.18784-24-vbabka@suse.cz> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=dDleZ4Lfyk2bTm2KE7iij6QxWvLTX00muEXEWoCAFGw=; b=iToBXoZPyX1HmEjRD9DYcj8MEGHopo9xF75hiJtC8KcXiSNm3wV+yNTOLZJg0tTXFp CcDnNBEVYlOJj98ra+ZqkK2W/NgaLZ60WNSJgEoN4NYNkCB2QB2oXRRd601ph8osCgLk fE+GP8Xg2NA97G7JWsO8n9Y/ekNxl+SIrugEV1BfoHGDD3YmGU6uuDIRymcZmbPOOIAe W4kbcehLY7lp4TcRp/BwMymv1KidNoHd+3va+GF5pSFIY8wfv9bThEhKSv+O5CUyk4Ct lvOqX4Y7g5dNI6Ub4pRj7+97axD/CYyvgWHXxLVdliIm6dJhbYT7xdDsSHD3MhaLjIsj SaMQ== Content-Disposition: inline In-Reply-To: <20211201181510.18784-24-vbabka-AlSwsSmVLrQ@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vlastimil Babka Cc: Matthew Wilcox , Christoph Lameter , David Rientjes , Joonsoo Kim , Pekka Enberg , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Andrew Morton , patches-cunTk1MwBs/YUNznpcFYbw@public.gmane.org, Michal Hocko , Vladimir Davydov , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Wed, Dec 01, 2021 at 07:15:00PM +0100, Vlastimil Babka wrote: > page->memcg_data is used with MEMCG_DATA_OBJCGS flag only for slab pages > so convert all the related infrastructure to struct slab. > > To avoid include cycles, move the inline definitions of slab_objcgs() and > slab_objcgs_check() from memcontrol.h to mm/slab.h. > > This is not just mechanistic changing of types and names. Now in > mem_cgroup_from_obj() we use PageSlab flag to decide if we interpret the page > as slab, instead of relying on MEMCG_DATA_OBJCGS bit checked in > page_objcgs_check() (now slab_objcgs_check()). Similarly in > memcg_slab_free_hook() where we can encounter kmalloc_large() pages (here the > PageSlab flag check is implied by virt_to_slab()). Yup, this is great. > @@ -2865,24 +2865,31 @@ int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, > */ > struct mem_cgroup *mem_cgroup_from_obj(void *p) > { > - struct page *page; > + struct folio *folio; > > if (mem_cgroup_disabled()) > return NULL; > > - page = virt_to_head_page(p); > + folio = virt_to_folio(p); > > /* > * Slab objects are accounted individually, not per-page. > * Memcg membership data for each individual object is saved in > * the page->obj_cgroups. > */ > - if (page_objcgs_check(page)) { > + if (folio_test_slab(folio)) { > + struct obj_cgroup **objcgs; > struct obj_cgroup *objcg; > + struct slab *slab; > unsigned int off; > > - off = obj_to_index(page->slab_cache, page_slab(page), p); > - objcg = page_objcgs(page)[off]; > + slab = folio_slab(folio); > + objcgs = slab_objcgs_check(slab); AFAICS the change to the _check() variant was accidental. folio_test_slab() makes sure it's a slab page, so the legit options for memcg_data are NULL or |MEMCG_DATA_OBJCGS; using slab_objcgs() here would include the proper asserts, like page_objcgs() used to. From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f177.google.com (mail-qk1-f177.google.com [209.85.222.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF17D168 for ; Tue, 14 Dec 2021 14:43:11 +0000 (UTC) Received: by mail-qk1-f177.google.com with SMTP id a11so16874561qkh.13 for ; Tue, 14 Dec 2021 06:43:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=dDleZ4Lfyk2bTm2KE7iij6QxWvLTX00muEXEWoCAFGw=; b=iToBXoZPyX1HmEjRD9DYcj8MEGHopo9xF75hiJtC8KcXiSNm3wV+yNTOLZJg0tTXFp CcDnNBEVYlOJj98ra+ZqkK2W/NgaLZ60WNSJgEoN4NYNkCB2QB2oXRRd601ph8osCgLk fE+GP8Xg2NA97G7JWsO8n9Y/ekNxl+SIrugEV1BfoHGDD3YmGU6uuDIRymcZmbPOOIAe W4kbcehLY7lp4TcRp/BwMymv1KidNoHd+3va+GF5pSFIY8wfv9bThEhKSv+O5CUyk4Ct lvOqX4Y7g5dNI6Ub4pRj7+97axD/CYyvgWHXxLVdliIm6dJhbYT7xdDsSHD3MhaLjIsj SaMQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=dDleZ4Lfyk2bTm2KE7iij6QxWvLTX00muEXEWoCAFGw=; b=NdcrX3HIiNFMAG+C1HFt7b0l2QtGkUks200VBUo0mfYxfI0kO2/91rMv3jez67KlCa 7yzrjx9O2Wn+x83w22poQKyM/a/8Ke1OjGlq7uHYn9ur8aasj8A7WTjfmROaly1X8V2d sSOXqzb1O1FcrPvmSFOKJODtr3CqARhFujDzMzJuOWP9YTFwcHW2fRWNxEUr4+vP+1yW cOXO2QoSCrK/2J8da91o/42iQzyamidGLJ7IEE7CPO9MEHQvW8/UCdhQhrMeR7Q0fA8T HsJMeIR8fkm2zg+f2yC3tOAYQnLYJh3f0bHiqn/3Ou3sm7B9RmrzsLIu2V+rHCHhMIRa Qjfg== X-Gm-Message-State: AOAM531i9bCg7DS6UUdABjEVsK5ueX/O40OGAHWhxRbRk/GSwp0C5Qr0 DAOD5H4DtwRkQqGb7lbdj5uxnQ== X-Google-Smtp-Source: ABdhPJwHSkFB7K2VjKuiDUuVy23sflYoaE0vwtJd3oSBAB2GpyxT+HEQZ0LfyomFTTrXctk3u+IJfg== X-Received: by 2002:a37:8d86:: with SMTP id p128mr4404337qkd.706.1639492990618; Tue, 14 Dec 2021 06:43:10 -0800 (PST) Received: from localhost ([2620:10d:c091:480::1:e1e4]) by smtp.gmail.com with ESMTPSA id x190sm6769qkb.115.2021.12.14.06.43.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Dec 2021 06:43:10 -0800 (PST) Date: Tue, 14 Dec 2021 15:43:07 +0100 From: Johannes Weiner To: Vlastimil Babka Cc: Matthew Wilcox , Christoph Lameter , David Rientjes , Joonsoo Kim , Pekka Enberg , linux-mm@kvack.org, Andrew Morton , patches@lists.linux.dev, Michal Hocko , Vladimir Davydov , cgroups@vger.kernel.org Subject: Re: [PATCH v2 23/33] mm/memcg: Convert slab objcgs from struct page to struct slab Message-ID: References: <20211201181510.18784-1-vbabka@suse.cz> <20211201181510.18784-24-vbabka@suse.cz> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211201181510.18784-24-vbabka@suse.cz> On Wed, Dec 01, 2021 at 07:15:00PM +0100, Vlastimil Babka wrote: > page->memcg_data is used with MEMCG_DATA_OBJCGS flag only for slab pages > so convert all the related infrastructure to struct slab. > > To avoid include cycles, move the inline definitions of slab_objcgs() and > slab_objcgs_check() from memcontrol.h to mm/slab.h. > > This is not just mechanistic changing of types and names. Now in > mem_cgroup_from_obj() we use PageSlab flag to decide if we interpret the page > as slab, instead of relying on MEMCG_DATA_OBJCGS bit checked in > page_objcgs_check() (now slab_objcgs_check()). Similarly in > memcg_slab_free_hook() where we can encounter kmalloc_large() pages (here the > PageSlab flag check is implied by virt_to_slab()). Yup, this is great. > @@ -2865,24 +2865,31 @@ int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, > */ > struct mem_cgroup *mem_cgroup_from_obj(void *p) > { > - struct page *page; > + struct folio *folio; > > if (mem_cgroup_disabled()) > return NULL; > > - page = virt_to_head_page(p); > + folio = virt_to_folio(p); > > /* > * Slab objects are accounted individually, not per-page. > * Memcg membership data for each individual object is saved in > * the page->obj_cgroups. > */ > - if (page_objcgs_check(page)) { > + if (folio_test_slab(folio)) { > + struct obj_cgroup **objcgs; > struct obj_cgroup *objcg; > + struct slab *slab; > unsigned int off; > > - off = obj_to_index(page->slab_cache, page_slab(page), p); > - objcg = page_objcgs(page)[off]; > + slab = folio_slab(folio); > + objcgs = slab_objcgs_check(slab); AFAICS the change to the _check() variant was accidental. folio_test_slab() makes sure it's a slab page, so the legit options for memcg_data are NULL or |MEMCG_DATA_OBJCGS; using slab_objcgs() here would include the proper asserts, like page_objcgs() used to.