From: Michal Hocko <mhocko@kernel.org>
To: Wei Yang <richard.weiyang@gmail.com>
Cc: trivial@kernel.org, akpm@linux-foundation.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3 1/2] mm/memblock.c: trivial code refine in memblock_is_region_memory()
Date: Thu, 22 Dec 2016 10:06:48 +0100 [thread overview]
Message-ID: <20161222090648.GB6048@dhcp22.suse.cz> (raw)
In-Reply-To: <1482363033-24754-2-git-send-email-richard.weiyang@gmail.com>
On Wed 21-12-16 23:30:32, Wei Yang wrote:
> memblock_is_region_memory() invoke memblock_search() to see whether the
> base address is in the memory region. If it fails, idx would be -1. Then,
> it returns 0.
>
> If the memblock_search() returns a valid index, it means the base address
> is guaranteed to be in the range memblock.memory.regions[idx]. Because of
> this, it is not necessary to check the base again.
>
> This patch removes the check on "base".
OK, the patch looks correct. I doubt it makes any real difference but I
do not see it being harmful.
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
> ---
> mm/memblock.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 7608bc3..4929e06 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1615,8 +1615,7 @@ int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size
>
> if (idx == -1)
> return 0;
> - return memblock.memory.regions[idx].base <= base &&
> - (memblock.memory.regions[idx].base +
> + return (memblock.memory.regions[idx].base +
> memblock.memory.regions[idx].size) >= end;
> }
>
> --
> 2.5.0
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2016-12-22 9:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-21 23:30 [PATCH V3 0/2] mm/memblock.c: fix potential bug and code refine Wei Yang
2016-12-21 23:30 ` [PATCH V3 1/2] mm/memblock.c: trivial code refine in memblock_is_region_memory() Wei Yang
2016-12-22 9:06 ` Michal Hocko [this message]
2016-12-21 23:30 ` [PATCH 2/2] mm/memblock.c: check return value of memblock_reserve() in memblock_virt_alloc_internal() Wei Yang
2016-12-22 9:15 ` Michal Hocko
2016-12-22 22:37 ` Wei Yang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161222090648.GB6048@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=richard.weiyang@gmail.com \
--cc=trivial@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).