From: Dirk Behme <dirk.behme@gmail.com>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores
Date: Fri, 18 Dec 2015 11:58:33 +0000 [thread overview]
Message-ID: <5673F4E9.9070205@gmail.com> (raw)
In-Reply-To: <CAMuHMdVVL9T6U8npb5kOLdP3PmS6Lhx0b9O3FKgxd2HQcUedFw@mail.gmail.com>
Hi Geert,
On 18.12.2015 12:02, Geert Uytterhoeven wrote:
> Hi Dirk,
>
> On Sat, Dec 12, 2015 at 8:16 AM, Dirk Behme <dirk.behme@gmail.com> wrote:
>> From: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>>
>> This patch adds Cortex-A53 CPU cores to r8a7795 SoC for a total of 8
>> cores (4 x Cortex-A57 + 4 x Cortex-A53).
>>
>> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>> Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
>
> Thanks, I can confirm this works.
>
> However, as the scheduler is not big.LITTLE aware (running processes are not
> migrated automatically to the faster CA57 cores when these are idle), it makes
> performance less deterministic.
What's the plan, then?
Waiting for big.LITTLE getting merged before enabling the A53? Or not
using the A53 at all?
Best regards
Dirk
WARNING: multiple messages have this Message-ID (diff)
From: dirk.behme@gmail.com (Dirk Behme)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores
Date: Fri, 18 Dec 2015 12:58:33 +0100 [thread overview]
Message-ID: <5673F4E9.9070205@gmail.com> (raw)
In-Reply-To: <CAMuHMdVVL9T6U8npb5kOLdP3PmS6Lhx0b9O3FKgxd2HQcUedFw@mail.gmail.com>
Hi Geert,
On 18.12.2015 12:02, Geert Uytterhoeven wrote:
> Hi Dirk,
>
> On Sat, Dec 12, 2015 at 8:16 AM, Dirk Behme <dirk.behme@gmail.com> wrote:
>> From: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>>
>> This patch adds Cortex-A53 CPU cores to r8a7795 SoC for a total of 8
>> cores (4 x Cortex-A57 + 4 x Cortex-A53).
>>
>> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>> Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
>
> Thanks, I can confirm this works.
>
> However, as the scheduler is not big.LITTLE aware (running processes are not
> migrated automatically to the faster CA57 cores when these are idle), it makes
> performance less deterministic.
What's the plan, then?
Waiting for big.LITTLE getting merged before enabling the A53? Or not
using the A53 at all?
Best regards
Dirk
WARNING: multiple messages have this Message-ID (diff)
From: Dirk Behme <dirk.behme@gmail.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linux-sh list <linux-sh@vger.kernel.org>,
Simon Horman <horms@verge.net.au>,
Geert Uytterhoeven <geert+renesas@glider.be>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Takeshi Kihara <takeshi.kihara.df@renesas.com>
Subject: Re: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores
Date: Fri, 18 Dec 2015 12:58:33 +0100 [thread overview]
Message-ID: <5673F4E9.9070205@gmail.com> (raw)
In-Reply-To: <CAMuHMdVVL9T6U8npb5kOLdP3PmS6Lhx0b9O3FKgxd2HQcUedFw@mail.gmail.com>
Hi Geert,
On 18.12.2015 12:02, Geert Uytterhoeven wrote:
> Hi Dirk,
>
> On Sat, Dec 12, 2015 at 8:16 AM, Dirk Behme <dirk.behme@gmail.com> wrote:
>> From: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>>
>> This patch adds Cortex-A53 CPU cores to r8a7795 SoC for a total of 8
>> cores (4 x Cortex-A57 + 4 x Cortex-A53).
>>
>> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>> Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
>
> Thanks, I can confirm this works.
>
> However, as the scheduler is not big.LITTLE aware (running processes are not
> migrated automatically to the faster CA57 cores when these are idle), it makes
> performance less deterministic.
What's the plan, then?
Waiting for big.LITTLE getting merged before enabling the A53? Or not
using the A53 at all?
Best regards
Dirk
next prev parent reply other threads:[~2015-12-18 11:58 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-12 7:16 [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores Dirk Behme
2015-12-12 7:16 ` Dirk Behme
2015-12-12 7:16 ` Dirk Behme
2015-12-12 7:16 ` [PATCH 2/2] arm64: dts: r8a7795: Add L2 cache-controller nodes Dirk Behme
2015-12-12 7:16 ` Dirk Behme
2015-12-12 7:16 ` Dirk Behme
2015-12-18 11:03 ` Geert Uytterhoeven
2015-12-18 11:03 ` Geert Uytterhoeven
2015-12-18 11:03 ` Geert Uytterhoeven
2015-12-18 11:56 ` Dirk Behme
2015-12-18 11:56 ` Dirk Behme
2015-12-18 11:56 ` Dirk Behme
2015-12-18 13:33 ` Geert Uytterhoeven
2015-12-18 13:33 ` Geert Uytterhoeven
2015-12-18 13:33 ` Geert Uytterhoeven
2015-12-18 13:46 ` Sudeep Holla
2015-12-18 13:46 ` Sudeep Holla
2015-12-18 13:46 ` Sudeep Holla
2015-12-18 11:02 ` [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores Geert Uytterhoeven
2015-12-18 11:02 ` Geert Uytterhoeven
2015-12-18 11:02 ` Geert Uytterhoeven
2015-12-18 11:58 ` Dirk Behme [this message]
2015-12-18 11:58 ` Dirk Behme
2015-12-18 11:58 ` Dirk Behme
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