From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Date: Fri, 18 Dec 2015 11:58:33 +0000 Subject: Re: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores Message-Id: <5673F4E9.9070205@gmail.com> List-Id: References: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hi Geert, On 18.12.2015 12:02, Geert Uytterhoeven wrote: > Hi Dirk, > > On Sat, Dec 12, 2015 at 8:16 AM, Dirk Behme wrote: >> From: Takeshi Kihara >> >> 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 >> Signed-off-by: Dirk Behme > > 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Subject: Re: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores Date: Fri, 18 Dec 2015 12:58:33 +0100 Message-ID: <5673F4E9.9070205@gmail.com> References: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-sh-owner@vger.kernel.org To: Geert Uytterhoeven Cc: Linux-sh list , Simon Horman , Geert Uytterhoeven , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Takeshi Kihara List-Id: devicetree@vger.kernel.org Hi Geert, On 18.12.2015 12:02, Geert Uytterhoeven wrote: > Hi Dirk, > > On Sat, Dec 12, 2015 at 8:16 AM, Dirk Behme wrote: >> From: Takeshi Kihara >> >> 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 >> Signed-off-by: Dirk Behme > > 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: dirk.behme@gmail.com (Dirk Behme) Date: Fri, 18 Dec 2015 12:58:33 +0100 Subject: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores In-Reply-To: References: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> Message-ID: <5673F4E9.9070205@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Geert, On 18.12.2015 12:02, Geert Uytterhoeven wrote: > Hi Dirk, > > On Sat, Dec 12, 2015 at 8:16 AM, Dirk Behme wrote: >> From: Takeshi Kihara >> >> 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 >> Signed-off-by: Dirk Behme > > 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