From: Feng Tang <feng.tang@intel.com>
To: Christoph Lameter <cl@gentwo.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Vlastimil Babka <vbabka@suse.cz>,
Roman Gushchin <roman.gushchin@linux.dev>,
Hyeonggon Yoo <42.hyeyoo@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
dave.hansen@intel.com, Robin Murphy <robin.murphy@arm.com>,
John Garry <john.garry@huawei.com>
Subject: Re: [PATCH v1] mm/slub: enable debugging memory wasting of kmalloc
Date: Fri, 1 Jul 2022 23:04:51 +0800 [thread overview]
Message-ID: <20220701150451.GA62281@shbuild999.sh.intel.com> (raw)
In-Reply-To: <alpine.DEB.2.22.394.2207011635040.588600@gentwo.de>
Hi Christoph,
On Fri, Jul 01, 2022 at 04:37:00PM +0200, Christoph Lameter wrote:
> On Fri, 1 Jul 2022, Feng Tang wrote:
>
> > static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
> > - unsigned long addr, struct kmem_cache_cpu *c)
> > + unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size)
> > {
>
> It would be good to avoid expanding the basic slab handling functions for
> kmalloc. Can we restrict the mods to the kmalloc related functions?
Yes, this is the part that concerned me. I tried but haven't figured
a way.
I started implemting it several month ago, and stuck with several
kmalloc APIs in a hacky way like dump_stack() when there is a waste
over 1/4 of the object_size of the kmalloc_caches[][].
Then I found one central API which has all the needed info (object_size &
orig_size) that we can yell about the waste :
static __always_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru,
gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
which I thought could be still hacky, as the existing 'alloc_traces'
can't be resued which already has the count/call-stack info. Current
solution leverage it at the cost of adding 'orig_size' parameters, but
I don't know how to pass the 'waste' info through as track/location is
in the lowest level.
Thanks,
Feng
next prev parent reply other threads:[~2022-07-01 15:05 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-01 13:59 [PATCH v1] mm/slub: enable debugging memory wasting of kmalloc Feng Tang
2022-07-01 14:37 ` Christoph Lameter
2022-07-01 15:04 ` Feng Tang [this message]
2022-07-03 14:17 ` Hyeonggon Yoo
2022-07-04 5:56 ` Feng Tang
2022-07-04 10:05 ` Hyeonggon Yoo
2022-07-05 2:34 ` Feng Tang
2022-07-11 8:15 ` Vlastimil Babka
2022-07-11 11:54 ` Feng Tang
2022-07-13 7:36 ` Feng Tang
2022-07-14 20:11 ` Vlastimil Babka
2022-07-15 8:29 ` Feng Tang
2022-07-19 13:45 ` Feng Tang
2022-07-19 14:39 ` Vlastimil Babka
2022-07-19 15:03 ` Feng Tang
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