From: Roman Gushchin <guro@fb.com>
To: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Kernel Team <Kernel-team@fb.com>,
"Johannes Weiner" <hannes@cmpxchg.org>,
Matthew Wilcox <willy@infradead.org>,
Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH] mm: refactor __vunmap() to avoid duplicated call to find_vm_area()
Date: Wed, 15 May 2019 17:18:05 +0000 [thread overview]
Message-ID: <20190515171800.GD9307@castle> (raw)
In-Reply-To: <78d9b650-4b47-60c5-4212-601c1719dba5@arm.com>
On Wed, May 15, 2019 at 09:57:11AM +0530, Anshuman Khandual wrote:
>
>
> On 05/15/2019 05:21 AM, Roman Gushchin wrote:
> > __vunmap() calls find_vm_area() twice without an obvious reason:
> > first directly to get the area pointer, second indirectly by calling
> > vm_remove_mappings()->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. Let's pass
> > a pointer to the vm_area instead of vm_struct to vm_remove_mappings(),
> > so it can pass it to __remove_vm_area() and avoid the redundant area
> > lookup.
> >
> > On my test setup, I've got 5-10% speed up on vfree()'ing 1000000
> > of 4-pages vmalloc blocks.
>
> Though results from 1000000 single page vmalloc blocks remain inconclusive,
> 4-page based vmalloc block's result shows improvement in the range of 5-10%.
So you can confirm my numbers? Great, thank you!
next prev parent reply other threads:[~2019-05-15 17:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-14 23:51 [PATCH] mm: refactor __vunmap() to avoid duplicated call to find_vm_area() Roman Gushchin
2019-05-14 23:51 ` [PATCH RESEND] mm: show number of vmalloc pages in /proc/meminfo Roman Gushchin
2019-05-15 7:14 ` Anshuman Khandual
2019-07-09 5:59 ` Minchan Kim
2019-07-10 1:31 ` Roman Gushchin
2019-05-15 4:27 ` [PATCH] mm: refactor __vunmap() to avoid duplicated call to find_vm_area() Anshuman Khandual
2019-05-15 17:18 ` Roman Gushchin [this message]
2019-05-15 7:41 ` Anshuman Khandual
2019-05-15 17:17 ` Roman Gushchin
2019-05-15 17:35 ` Ira Weiny
2019-05-15 17:45 ` Roman Gushchin
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