From: Vlastimil Babka <vbabka@suse.cz>
To: Roman Gushchin <guroan@gmail.com>, linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org,
Matthew Wilcox <willy@infradead.org>,
Johannes Weiner <hannes@cmpxchg.org>,
kernel-team@fb.com, Roman Gushchin <guro@fb.com>
Subject: Re: [PATCH 1/3] mm: refactor __vunmap() to avoid duplicated call to find_vm_area()
Date: Thu, 28 Feb 2019 16:00:02 +0100 [thread overview]
Message-ID: <dfc87917-c206-ccd1-64f0-c45b86f52cda@suse.cz> (raw)
In-Reply-To: <20190225203037.1317-2-guro@fb.com>
On 2/25/19 9:30 PM, Roman Gushchin wrote:
> __vunmap() calls find_vm_area() twice without an obvious reason:
> first directly to get the area pointer, second indirectly by calling
> remove_vm_area(), which is again searching for the area.
>
> To remove this redundancy, let's split remove_vm_area() into
> __remove_vm_area(struct vmap_area *), which performs the actual area
> removal, and remove_vm_area(const void *addr) wrapper, which can
> be used everywhere, where it has been used before.
>
> On my test setup, I've got 5-10% speed up on vfree()'ing 1000000
> of 4-pages vmalloc blocks.
>
> Perf report before:
> 22.64% cat [kernel.vmlinux] [k] free_pcppages_bulk
> 10.30% cat [kernel.vmlinux] [k] __vunmap
> 9.80% cat [kernel.vmlinux] [k] find_vmap_area
> 8.11% cat [kernel.vmlinux] [k] vunmap_page_range
> 4.20% cat [kernel.vmlinux] [k] __slab_free
> 3.56% cat [kernel.vmlinux] [k] __list_del_entry_valid
> 3.46% cat [kernel.vmlinux] [k] smp_call_function_many
> 3.33% cat [kernel.vmlinux] [k] kfree
> 3.32% cat [kernel.vmlinux] [k] free_unref_page
>
> Perf report after:
> 23.01% cat [kernel.kallsyms] [k] free_pcppages_bulk
> 9.46% cat [kernel.kallsyms] [k] __vunmap
> 9.15% cat [kernel.kallsyms] [k] vunmap_page_range
> 6.17% cat [kernel.kallsyms] [k] __slab_free
> 5.61% cat [kernel.kallsyms] [k] kfree
> 4.86% cat [kernel.kallsyms] [k] bad_range
> 4.67% cat [kernel.kallsyms] [k] free_unref_page_commit
> 4.24% cat [kernel.kallsyms] [k] __list_del_entry_valid
> 3.68% cat [kernel.kallsyms] [k] free_unref_page
> 3.65% cat [kernel.kallsyms] [k] __list_add_valid
> 3.19% cat [kernel.kallsyms] [k] __purge_vmap_area_lazy
> 3.10% cat [kernel.kallsyms] [k] find_vmap_area
> 3.05% cat [kernel.kallsyms] [k] rcu_cblist_dequeue
>
> Signed-off-by: Roman Gushchin <guro@fb.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Matthew Wilcox <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
next prev parent reply other threads:[~2019-02-28 15:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190225203037.1317-1-guro@fb.com>
2019-02-25 20:30 ` Roman Gushchin
2019-02-28 15:00 ` Vlastimil Babka [this message]
2019-02-25 20:30 ` [PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area() Roman Gushchin
2019-03-01 14:43 ` Vlastimil Babka
2019-03-01 16:48 ` Roman Gushchin
2019-04-17 13:27 ` Vlastimil Babka
2019-04-17 19:15 ` Roman Gushchin
2019-02-25 20:30 ` [PATCH 3/3] mm: show number of vmalloc pages in /proc/meminfo Roman Gushchin
2019-03-01 15:05 ` Vlastimil Babka
2019-04-17 13:34 ` Vlastimil Babka
2019-03-29 22:07 ` [PATCH 0/3] vmalloc enhancements Roman Gushchin
2019-04-17 13:36 ` Vlastimil Babka
2018-12-19 17:37 Roman Gushchin
2018-12-19 17:37 ` [PATCH 1/3] mm: refactor __vunmap() to avoid duplicated call to find_vm_area() Roman Gushchin
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