From: Johannes Weiner <hannes@cmpxchg.org>
To: Roman Gushchin <guro@fb.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
Michal Hocko <mhocko@kernel.org>,
Shakeel Butt <shakeelb@google.com>,
linux-mm@kvack.org, Vlastimil Babka <vbabka@suse.cz>,
kernel-team@fb.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 04/19] mm: slub: implement SLUB version of obj_to_index()
Date: Wed, 27 May 2020 15:44:55 -0400 [thread overview]
Message-ID: <20200527194455.GB47905@cmpxchg.org> (raw)
In-Reply-To: <20200526214227.989341-5-guro@fb.com>
On Tue, May 26, 2020 at 02:42:12PM -0700, Roman Gushchin wrote:
> This commit implements SLUB version of the obj_to_index() function,
> which will be required to calculate the offset of obj_cgroup in the
> obj_cgroups vector to store/obtain the objcg ownership data.
>
> To make it faster, let's repeat the SLAB's trick introduced by
> commit 6a2d7a955d8d ("[PATCH] SLAB: use a multiply instead of a
> divide in obj_to_index()") and avoid an expensive division.
>
> Vlastimil Babka noticed, that SLUB does have already a similar
> function called slab_index(), which is defined only if SLUB_DEBUG
> is enabled. The function does a similar math, but with a division,
> and it also takes a page address instead of a page pointer.
>
> Let's remove slab_index() and replace it with the new helper
> __obj_to_index(), which takes a page address. obj_to_index()
> will be a simple wrapper taking a page pointer and passing
> page_address(page) into __obj_to_index().
>
> Signed-off-by: Roman Gushchin <guro@fb.com>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
next prev parent reply other threads:[~2020-05-27 19:45 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 21:42 [PATCH v4 00/19] The new cgroup slab memory controller Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 02/19] mm: memcg: prepare for byte-sized vmstat items Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 03/19] mm: memcg: convert vmstat slab counters to bytes Roman Gushchin
2020-05-27 11:43 ` Vlastimil Babka
2020-05-27 16:25 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 04/19] mm: slub: implement SLUB version of obj_to_index() Roman Gushchin
2020-05-27 19:44 ` Johannes Weiner [this message]
2020-05-26 21:42 ` [PATCH v4 05/19] mm: memcontrol: decouple reference counting from page accounting Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 06/19] mm: memcg/slab: obj_cgroup API Roman Gushchin
2020-05-27 19:56 ` Johannes Weiner
2020-05-27 20:03 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 07/19] mm: memcg/slab: allocate obj_cgroups for non-root slab pages Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 09/19] mm: memcg/slab: charge individual slab objects instead of pages Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo Roman Gushchin
2020-05-27 15:54 ` Vlastimil Babka
2020-05-27 16:28 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 11/19] mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 12/19] mm: memcg/slab: use a single set of kmem_caches for all accounted allocations Roman Gushchin
2020-05-27 16:01 ` Vlastimil Babka
2020-05-27 16:29 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 13/19] mm: memcg/slab: simplify memcg cache creation Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 14/19] mm: memcg/slab: remove memcg_kmem_get_cache() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 15/19] mm: memcg/slab: deprecate slab_root_caches Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 16/19] mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 17/19] mm: memcg/slab: use a single set of kmem_caches for all allocations Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 18/19] kselftests: cgroup: add kernel memory accounting tests Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 19/19] tools/cgroup: add memcg_slabinfo.py tool Roman Gushchin
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