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 ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wcSX92BCvzDqFW for ; Tue, 30 May 2017 19:11:21 +1000 (AEST) In-Reply-To: <20170512035810.15070-1-andrew@aj.id.au> To: Andrew Jeffery , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Cc: Andrew Jeffery , linux-kernel@vger.kernel.org, npiggin@gmail.com, paulus@samba.org, anton@samba.org Subject: Re: powerpc: Tweak copy selection parameter in __copy_tofrom_user_power7() Message-Id: <3wcSX91fQYz9s78@ozlabs.org> Date: Tue, 30 May 2017 19:11:21 +1000 (AEST) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2017-05-12 at 03:58:10 UTC, Andrew Jeffery wrote: > Experiments with the netperf benchmark indicated that the size selecting > VMX-based copies in __copy_tofrom_user_power7() was suboptimal on POWER8. > Measurements showed that parity was in the neighbourhood of 3328 bytes, > rather than greater than 4096. The change gives a 1.5-2.0% improvement in > performance for 4096-byte buffers, reducing the relative time spent in > __copy_tofrom_user_power7() from approximately 7% to approximately 5% in > the TCP_RR benchmark. > > Signed-off-by: Andrew Jeffery > Acked-by: Anton Blanchard Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/a3f952df3c6d205fe3b1e0e4848d3c cheers