From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 70DC71A0D8C for ; Mon, 7 Dec 2015 21:30:47 +1100 (AEDT) In-Reply-To: <1446079451-8774-2-git-send-email-anton@samba.org> To: Anton Blanchard , benh@kernel.crashing.org, paulus@samba.org, mikey@neuling.org, cyrilbur@gmail.com, scottwood@freescale.com From: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org Subject: Re: [01/19] powerpc: Don't disable kernel FP/VMX/VSX MSR bits on context switch Message-Id: <20151207103047.305AD1402D2@ozlabs.org> Date: Mon, 7 Dec 2015 21:30:47 +1100 (AEDT) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2015-29-10 at 00:43:53 UTC, Anton Blanchard wrote: > Writing the MSR is slow, so we want to avoid it whenever possible. > > A subsequent patch will add a debug option that strictly manages the > FP/VMX/VSX unavailable bits. For now just remove it, matching what > we do in other areas of the kernel (eg enable_kernel_altivec()). > > A context switch microbenchmark using yield(): > > http://ozlabs.org/~anton/junkcode/context_switch2.c > > ./context_switch2 --test=yield --fp 0 0 > > shows an improvement of almost 3% on POWER8. > > Signed-off-by: Anton Blanchard Applied all 19 patches to powerpc next, thanks. http://git.kernel.org/cgit/linux/kernel/git/powerpc/linux.git/log/?h=next cheers