Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754327AbaLDRpq (ORCPT ); Thu, 4 Dec 2014 12:45:46 -0500 Received: from mail-qc0-f175.google.com ([209.85.216.175]:54678 "EHLO mail-qc0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751583AbaLDRpo (ORCPT ); Thu, 4 Dec 2014 12:45:44 -0500 MIME-Version: 1.0 In-Reply-To: <1417687974-18681-1-git-send-email-daniel.vetter@ffwll.ch> References: <1417166995-10803-1-git-send-email-daniel.vetter@ffwll.ch> <1417687974-18681-1-git-send-email-daniel.vetter@ffwll.ch> Date: Thu, 4 Dec 2014 09:45:44 -0800 Message-ID: Subject: Re: [PATCH] drm/i915: compute wait_ioctl timeout correctly From: John Stultz To: Daniel Vetter Cc: Intel Graphics Development , LKML , Chris Wilson , Dave Gordon , Thomas Gleixner , Daniel Vetter Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 4, 2014 at 2:12 AM, Daniel Vetter wrote: > We've lost the +1 required for correct timeouts in > > commit 5ed0bdf21a85d78e04f89f15ccf227562177cbd9 > Author: Thomas Gleixner > Date: Wed Jul 16 21:05:06 2014 +0000 > > drm: i915: Use nsec based interfaces > > Use ktime_get_raw_ns() and get rid of the back and forth timespec > conversions. > > Signed-off-by: Thomas Gleixner > Acked-by: Daniel Vetter > Signed-off-by: John Stultz > > So fix this up by reinstating our handrolled _timeout function. While > at it bother with handling MAX_JIFFIES. > > v2: Convert to usecs (we don't care about the accuracy anyway) first > to avoid overflow issues Dave Gordon spotted. > > v3: Drop the explicit MAX_JIFFY_OFFSET check, usecs_to_jiffies should > take care of that already. It might be a bit too enthusiastic about it > though. > > v4: Chris has a much nicer color, so use his implementation. > > This requires to export nsec_to_jiffies from time.c. > > Cc: Chris Wilson > Cc: Dave Gordon > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82749 > Cc: Thomas Gleixner > Cc: John Stultz > Signed-off-by: Daniel Vetter > --- > drivers/gpu/drm/i915/i915_drv.h | 5 +++++ > drivers/gpu/drm/i915/i915_gem.c | 3 ++- > kernel/time/time.c | 1 + > 3 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 049482f5d9ac..564a45f4a0ab 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -3097,6 +3097,11 @@ static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m) > return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1); > } > > +static inline unsigned long nsecs_to_jiffies_timeout(const u64 n) > +{ > + return min_t(u64, MAX_JIFFY_OFFSET, nsecs_to_jiffies64(n) + 1); > +} > + > static inline unsigned long > timespec_to_jiffies_timeout(const struct timespec *value) > { > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index 9d362d320d82..04a9f26407ae 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -1226,7 +1226,8 @@ int __i915_wait_request(struct drm_i915_gem_request *req, > if (i915_gem_request_completed(req, true)) > return 0; > > - timeout_expire = timeout ? jiffies + nsecs_to_jiffies((u64)*timeout) : 0; > + timeout_expire = timeout ? > + jiffies + nsecs_to_jiffies_timeout((u64)*timeout) : 0; > > if (INTEL_INFO(dev)->gen >= 6 && ring->id == RCS && can_wait_boost(file_priv)) { > gen6_rps_boost(dev_priv); > diff --git a/kernel/time/time.c b/kernel/time/time.c > index a9ae20fb0b11..8fae82ca5cbf 100644 > --- a/kernel/time/time.c > +++ b/kernel/time/time.c > @@ -745,6 +745,7 @@ u64 nsecs_to_jiffies64(u64 n) > return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); > #endif > } > +EXPORT_SYMBOL(nsecs_to_jiffies64); For the sake of the fix, Acked-by: John Stultz But I'll likely follow this (eventually - since its going through the drm tree) with a cleanup patch moving nsecs_to_jiffies_timeout over to time.c. thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/