From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEDFDC47253 for ; Fri, 1 May 2020 11:04:10 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9E8E8208C3 for ; Fri, 1 May 2020 11:04:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9E8E8208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 261B56E07B; Fri, 1 May 2020 11:04:10 +0000 (UTC) X-Greylist: delayed 1310 seconds by postgrey-1.36 at gabe; Fri, 01 May 2020 11:04:08 UTC Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9ADCF6E07B; Fri, 1 May 2020 11:04:08 +0000 (UTC) Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1jUT7Y-0003fF-19; Fri, 01 May 2020 12:42:16 +0200 Date: Fri, 1 May 2020 12:42:15 +0200 From: Sebastian Andrzej Siewior To: "Jason A. Donenfeld" Message-ID: <20200501104215.s2eftchxm66lmbvj@linutronix.de> References: <20200430221016.3866-1-Jason@zx2c4.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200430221016.3866-1-Jason@zx2c4.com> Subject: Re: [Intel-gfx] [PATCH] drm/i915: check to see if SIMD registers are available before using SIMD X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, chris@chris-wilson.co.uk, dri-devel@lists.freedesktop.org, tglx@linutronix.de Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 2020-04-30 16:10:16 [-0600], Jason A. Donenfeld wrote: > Sometimes it's not okay to use SIMD registers, the conditions for which > have changed subtly from kernel release to kernel release. Usually the > pattern is to check for may_use_simd() and then fallback to using > something slower in the unlikely case SIMD registers aren't available. > So, this patch fixes up i915's accelerated memcpy routines to fallback > to boring memcpy if may_use_simd() is false. That would indicate that these functions are used from IRQ/softirq which break otherwise if the kernel is also using the registers. The crypto code uses it for that purpose. So Reviewed-by: Sebastian Andrzej Siewior May I ask how large the memcpy can be? I'm asking in case it is large and an explicit rescheduling point might be needed. > Cc: stable@vger.kernel.org > Signed-off-by: Jason A. Donenfeld Sebastian _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx