From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Date: Fri, 18 Dec 2015 11:02:42 +0000 Subject: Re: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores Message-Id: List-Id: References: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> In-Reply-To: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org 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. Hence we would like to postpone this. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores Date: Fri, 18 Dec 2015 12:02:42 +0100 Message-ID: References: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> Sender: linux-sh-owner@vger.kernel.org To: Dirk Behme 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 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. Hence we would like to postpone this. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: geert@linux-m68k.org (Geert Uytterhoeven) Date: Fri, 18 Dec 2015 12:02:42 +0100 Subject: [PATCH 1/2] arm64: dts: r8a7795: Add Cortex-A53 CPU cores In-Reply-To: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> References: <1449904607-4060-1-git-send-email-dirk.behme@gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Hence we would like to postpone this. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds