From: Will Deacon <will@kernel.org>
To: Prathu Baronia <prathubaronia2011@gmail.com>
Cc: linux-kernel@vger.kernel.org, chintan.pandya@oneplus.com,
Prathu Baronia <prathu.baronia@oneplus.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
"glider@google.com" <glider@google.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Andrew Morton <akpm@linux-foundation.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Andrey Konovalov <andreyknvl@google.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 0/1] mm: Optimizing hugepage zeroing in arm64
Date: Thu, 21 Jan 2021 17:46:16 +0000 [thread overview]
Message-ID: <20210121174616.GA22740@willie-the-truck> (raw)
In-Reply-To: <20210121165153.17828-1-prathu.baronia@oneplus.com>
On Thu, Jan 21, 2021 at 10:21:50PM +0530, Prathu Baronia wrote:
> This patch removes the unnecessary kmap calls in the hugepage zeroing path and
> improves the timing by 62%.
>
> I had proposed a similar change in Apr-May'20 timeframe in memory.c where I
> proposed to clear out a hugepage by directly calling a memset over the whole
> hugepage but got the opposition that the change was not architecturally neutral.
>
> Upon revisiting this now I see significant improvement by removing around 2k
> barrier calls from the zeroing path. So hereby I propose an arm64 specific
> definition of clear_user_highpage().
Given that barrier() is purely a thing for the compiler, wouldn't the same
change yield a benefit on any other architecture without HIGHMEM? In which
case, I think this sort of change belongs in the core code if it's actually
worthwhile.
Will
next prev parent reply other threads:[~2021-01-21 17:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 16:51 [PATCH 0/1] mm: Optimizing hugepage zeroing in arm64 Prathu Baronia
2021-01-21 16:51 ` [PATCH 1/1] " Prathu Baronia
2021-01-21 17:46 ` Will Deacon [this message]
2021-01-21 18:59 ` [PATCH 0/1] " Robin Murphy
2021-01-22 12:13 ` Catalin Marinas
2021-01-22 12:45 ` Robin Murphy
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