From: Will Deacon <will@kernel.org>
To: Gaurav Kohli <gkohli@codeaurora.org>
Cc: maz@kernel.org, neeraju@codeaurora.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH] arm64: Skip apply SSBS call for non SSBS system
Date: Wed, 12 Aug 2020 14:30:44 +0100 [thread overview]
Message-ID: <20200812133043.GA8924@willie-the-truck> (raw)
In-Reply-To: <1596550484-11029-1-git-send-email-gkohli@codeaurora.org>
On Tue, Aug 04, 2020 at 07:44:42PM +0530, Gaurav Kohli wrote:
> In a system where no cpu's implement SSBS, for
> them no need to set pstate. This might help to save
> few cpu cycles during context switch.
>
> Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
>
> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> index 6089638..79f80f1 100644
> --- a/arch/arm64/kernel/process.c
> +++ b/arch/arm64/kernel/process.c
> @@ -477,6 +477,13 @@ static void ssbs_thread_switch(struct task_struct *next)
> struct pt_regs *regs = task_pt_regs(next);
>
> /*
> + * For Targets which don't have SSBS support, they
> + * can return from here.
> + */
> + if (!IS_ENABLED(CONFIG_ARM64_SSBD))
> + return;
Does this actually make a measurable difference?
Will
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next prev parent reply other threads:[~2020-08-12 13:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-04 14:14 [PATCH] arm64: Skip apply SSBS call for non SSBS system Gaurav Kohli
2020-08-04 14:14 ` [PATCH] nvmem: core: add support to NVMEM_NO_SYSFS_ENTRY Gaurav Kohli
2020-08-04 14:25 ` Gaurav Kohli
2020-08-04 14:14 ` [PATCH] nvmem: core: add NVMEM_SYSFS Kconfig Gaurav Kohli
2020-08-04 14:26 ` Gaurav Kohli
2020-08-11 4:48 ` [PATCH] arm64: Skip apply SSBS call for non SSBS system Gaurav Kohli
2020-08-12 13:30 ` Will Deacon [this message]
2020-08-12 14:15 ` Gaurav Kohli
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