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=-14.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 11604C432BE for ; Tue, 27 Jul 2021 07:11:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E80B0611C7 for ; Tue, 27 Jul 2021 07:11:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235742AbhG0HLy (ORCPT ); Tue, 27 Jul 2021 03:11:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235409AbhG0HLw (ORCPT ); Tue, 27 Jul 2021 03:11:52 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07AD9C061757; Tue, 27 Jul 2021 00:11:53 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id f14-20020a05600c154eb02902519e4abe10so1075766wmg.4; Tue, 27 Jul 2021 00:11:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=sxFcXJToDZMWgKe9LXihsrB1La88hBN0XlIyclx9/f4=; b=lEwkbL1rJM3F+mDQtqOuqfdOKPbBUOy0nmusGJjX0L5q1YZx4htOz5BKUJfkjr0piO CY09atvv4CfAk0NzHPj9jUDGJOSCtbJNnxqJyC9tbWfiHqlBNYMUDNKX4KIwZmFJOaW2 qTTlAUaE1yMSabskDSytArp1jmYkizKRsVZueOY/3G1p+GghiUTGbmouLXY6zHnunsjO s8FT3oi0Wfiqo6Fs1W3THmkyZDlTpxmz3ZOe+atFKCudwAcB3tqM4PSwO7pPnYwXq1cs SGGOjMe1KVNTvXj+XsJ84gOdHT/ZsmBvWMr7VgLf9oOjAoQGWQ6XqOvNoAOxblkgd10m dxBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=sxFcXJToDZMWgKe9LXihsrB1La88hBN0XlIyclx9/f4=; b=Chj/xoHuYvn+lRZa98PMaOuqXCToiQ6S25bIy5RosUviLZHnCttSep1dfhNm39Z55B 6oWH2qZVqXX8heCon6mmstYbOurdlv8Qb+s/qn4tvoZ04JmCQDZRAkmGxNbytHGy6eY/ wahtajjEXMu82nJoGj3Wkz5CDozQ4q160aI4nVIbUbnsOCWMtUSQrGzHcvt87iHJMUJ8 COEwdJ75p62CwPkEvTw/lTPGTk7FZJLuOhvdGzoc52r3odsMPFE1i3VCoEVq7b7F+vaw 1JuyG+hraZppKwv0jfomhJeEtplScdDN4cwMAbe3d4CTyc/hFLskQIxeTLiLBYgL2pOK pgAA== X-Gm-Message-State: AOAM532eMzu4j7/EVXkzSo1t36TuBP5bxoO/ckraz86ku3uTRp5/nuUW WNOQgKQPI86JowI+6ioq41olzUXOqsA= X-Google-Smtp-Source: ABdhPJz/MgnHtkxYirTPDve81q42RkzbN1vyC5mjRajaoM6gwdEzfJ2NEGQCc32h6XQNzHYHd+Rkxg== X-Received: by 2002:a7b:c108:: with SMTP id w8mr20709070wmi.99.1627369911654; Tue, 27 Jul 2021 00:11:51 -0700 (PDT) Received: from ?IPv6:2a02:908:1252:fb60:ae22:6310:9a31:9877? ([2a02:908:1252:fb60:ae22:6310:9a31:9877]) by smtp.gmail.com with ESMTPSA id m9sm881309wrz.75.2021.07.27.00.11.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 27 Jul 2021 00:11:51 -0700 (PDT) Subject: Re: [RFC 1/4] dma-fence: Add deadline awareness To: Rob Clark , dri-devel@lists.freedesktop.org Cc: Daniel Vetter , Matthew Brost , Rob Clark , Sumit Semwal , Gustavo Padovan , =?UTF-8?Q?Christian_K=c3=b6nig?= , "open list:SYNC FILE FRAMEWORK" , "moderated list:DMA BUFFER SHARING FRAMEWORK" , open list References: <20210726233854.2453899-1-robdclark@gmail.com> <20210726233854.2453899-2-robdclark@gmail.com> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: <50b181fe-6605-b7ac-36a6-8bcda2930e6f@gmail.com> Date: Tue, 27 Jul 2021 09:11:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210726233854.2453899-2-robdclark@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 27.07.21 um 01:38 schrieb Rob Clark: > From: Rob Clark > > Add a way to hint to the fence signaler of an upcoming deadline, such as > vblank, which the fence waiter would prefer not to miss. This is to aid > the fence signaler in making power management decisions, like boosting > frequency as the deadline approaches and awareness of missing deadlines > so that can be factored in to the frequency scaling. > > Signed-off-by: Rob Clark > --- > drivers/dma-buf/dma-fence.c | 39 +++++++++++++++++++++++++++++++++++++ > include/linux/dma-fence.h | 17 ++++++++++++++++ > 2 files changed, 56 insertions(+) > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c > index ce0f5eff575d..2e0d25ab457e 100644 > --- a/drivers/dma-buf/dma-fence.c > +++ b/drivers/dma-buf/dma-fence.c > @@ -910,6 +910,45 @@ dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count, > } > EXPORT_SYMBOL(dma_fence_wait_any_timeout); > > + > +/** > + * dma_fence_set_deadline - set desired fence-wait deadline > + * @fence: the fence that is to be waited on > + * @deadline: the time by which the waiter hopes for the fence to be > + * signaled > + * > + * Inform the fence signaler of an upcoming deadline, such as vblank, by > + * which point the waiter would prefer the fence to be signaled by. This > + * is intended to give feedback to the fence signaler to aid in power > + * management decisions, such as boosting GPU frequency if a periodic > + * vblank deadline is approaching. > + */ > +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline) > +{ > + unsigned long flags; > + > + if (dma_fence_is_signaled(fence)) > + return; > + > + spin_lock_irqsave(fence->lock, flags); > + > + /* If we already have an earlier deadline, keep it: */ > + if (test_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &fence->flags) && > + ktime_before(fence->deadline, deadline)) { > + spin_unlock_irqrestore(fence->lock, flags); > + return; > + } > + > + fence->deadline = deadline; > + set_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &fence->flags); > + > + spin_unlock_irqrestore(fence->lock, flags); > + > + if (fence->ops->set_deadline) > + fence->ops->set_deadline(fence, deadline); > +} > +EXPORT_SYMBOL(dma_fence_set_deadline); > + > /** > * dma_fence_init - Initialize a custom fence. > * @fence: the fence to initialize > diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h > index 6ffb4b2c6371..4e6cfe4e6fbc 100644 > --- a/include/linux/dma-fence.h > +++ b/include/linux/dma-fence.h > @@ -88,6 +88,7 @@ struct dma_fence { > /* @timestamp replaced by @rcu on dma_fence_release() */ > struct rcu_head rcu; > }; > + ktime_t deadline; Mhm, adding the flag sounds ok to me but I'm a bit hesitating adding the deadline as extra field here. We tuned the dma_fence structure intentionally so that it is only 64 bytes. Regards, Christian. > u64 context; > u64 seqno; > unsigned long flags; > @@ -99,6 +100,7 @@ enum dma_fence_flag_bits { > DMA_FENCE_FLAG_SIGNALED_BIT, > DMA_FENCE_FLAG_TIMESTAMP_BIT, > DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, > + DMA_FENCE_FLAG_HAS_DEADLINE_BIT, > DMA_FENCE_FLAG_USER_BITS, /* must always be last member */ > }; > > @@ -261,6 +263,19 @@ struct dma_fence_ops { > */ > void (*timeline_value_str)(struct dma_fence *fence, > char *str, int size); > + > + /** > + * @set_deadline: > + * > + * Callback to allow a fence waiter to inform the fence signaler of an > + * upcoming deadline, such as vblank, by which point the waiter would > + * prefer the fence to be signaled by. This is intended to give feedback > + * to the fence signaler to aid in power management decisions, such as > + * boosting GPU frequency. > + * > + * This callback is optional. > + */ > + void (*set_deadline)(struct dma_fence *fence, ktime_t deadline); > }; > > void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, > @@ -586,6 +601,8 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) > return ret < 0 ? ret : 0; > } > > +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline); > + > struct dma_fence *dma_fence_get_stub(void); > struct dma_fence *dma_fence_allocate_private_stub(void); > u64 dma_fence_context_alloc(unsigned num); 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=-12.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 0EA76C4338F for ; Tue, 27 Jul 2021 07:11:55 +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 C4DF161179 for ; Tue, 27 Jul 2021 07:11:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C4DF161179 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 43BF36E530; Tue, 27 Jul 2021 07:11:54 +0000 (UTC) Received: from mail-wm1-x32e.google.com (mail-wm1-x32e.google.com [IPv6:2a00:1450:4864:20::32e]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2804B6E530 for ; Tue, 27 Jul 2021 07:11:53 +0000 (UTC) Received: by mail-wm1-x32e.google.com with SMTP id u15-20020a05600c19cfb02902501bdb23cdso1123768wmq.0 for ; Tue, 27 Jul 2021 00:11:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=sxFcXJToDZMWgKe9LXihsrB1La88hBN0XlIyclx9/f4=; b=lEwkbL1rJM3F+mDQtqOuqfdOKPbBUOy0nmusGJjX0L5q1YZx4htOz5BKUJfkjr0piO CY09atvv4CfAk0NzHPj9jUDGJOSCtbJNnxqJyC9tbWfiHqlBNYMUDNKX4KIwZmFJOaW2 qTTlAUaE1yMSabskDSytArp1jmYkizKRsVZueOY/3G1p+GghiUTGbmouLXY6zHnunsjO s8FT3oi0Wfiqo6Fs1W3THmkyZDlTpxmz3ZOe+atFKCudwAcB3tqM4PSwO7pPnYwXq1cs SGGOjMe1KVNTvXj+XsJ84gOdHT/ZsmBvWMr7VgLf9oOjAoQGWQ6XqOvNoAOxblkgd10m dxBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=sxFcXJToDZMWgKe9LXihsrB1La88hBN0XlIyclx9/f4=; b=MQtSl58rrHmIFRv2dvvQ2pjkrO2zEV4OwaTmGZHc9tslasid15w0HPLxLeqOUoWTHz 7BcQk9qKxGekUbdehBU628FNq8PVYX0JWL+iUFYoC51ecqjCYSPJMhKIevtQsR1l9SaB B0fUIAFk3uFNHIcXMoHpV6qHOsk7UMm5e2FzaYl1sL6A5v3B9pF/VleLU28+NrQYAy/6 wTT9vSIG4W0PvACXXOlDGsQyLZbTxLW9eszkCvtJGII6HQn2YsjktKKcMckwMxuNfYH9 lXgZIUUhsnVdtKLS80R8n+1d5huFL3+xE0KZsoUzHZx594xl4tk0uPcoquy4AYPHViYr Y57A== X-Gm-Message-State: AOAM532TAeMQv4d4SLihfo1NoF6V0zMUXE6wHs2kZgBdge4nROsBuHGu DZ9q5CVfxm3GjNeUXTXeDpk= X-Google-Smtp-Source: ABdhPJz/MgnHtkxYirTPDve81q42RkzbN1vyC5mjRajaoM6gwdEzfJ2NEGQCc32h6XQNzHYHd+Rkxg== X-Received: by 2002:a7b:c108:: with SMTP id w8mr20709070wmi.99.1627369911654; Tue, 27 Jul 2021 00:11:51 -0700 (PDT) Received: from ?IPv6:2a02:908:1252:fb60:ae22:6310:9a31:9877? ([2a02:908:1252:fb60:ae22:6310:9a31:9877]) by smtp.gmail.com with ESMTPSA id m9sm881309wrz.75.2021.07.27.00.11.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 27 Jul 2021 00:11:51 -0700 (PDT) Subject: Re: [RFC 1/4] dma-fence: Add deadline awareness To: Rob Clark , dri-devel@lists.freedesktop.org References: <20210726233854.2453899-1-robdclark@gmail.com> <20210726233854.2453899-2-robdclark@gmail.com> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: <50b181fe-6605-b7ac-36a6-8bcda2930e6f@gmail.com> Date: Tue, 27 Jul 2021 09:11:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210726233854.2453899-2-robdclark@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Matthew Brost , Rob Clark , Gustavo Padovan , open list , "moderated list:DMA BUFFER SHARING FRAMEWORK" , =?UTF-8?Q?Christian_K=c3=b6nig?= , "open list:SYNC FILE FRAMEWORK" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Am 27.07.21 um 01:38 schrieb Rob Clark: > From: Rob Clark > > Add a way to hint to the fence signaler of an upcoming deadline, such as > vblank, which the fence waiter would prefer not to miss. This is to aid > the fence signaler in making power management decisions, like boosting > frequency as the deadline approaches and awareness of missing deadlines > so that can be factored in to the frequency scaling. > > Signed-off-by: Rob Clark > --- > drivers/dma-buf/dma-fence.c | 39 +++++++++++++++++++++++++++++++++++++ > include/linux/dma-fence.h | 17 ++++++++++++++++ > 2 files changed, 56 insertions(+) > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c > index ce0f5eff575d..2e0d25ab457e 100644 > --- a/drivers/dma-buf/dma-fence.c > +++ b/drivers/dma-buf/dma-fence.c > @@ -910,6 +910,45 @@ dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count, > } > EXPORT_SYMBOL(dma_fence_wait_any_timeout); > > + > +/** > + * dma_fence_set_deadline - set desired fence-wait deadline > + * @fence: the fence that is to be waited on > + * @deadline: the time by which the waiter hopes for the fence to be > + * signaled > + * > + * Inform the fence signaler of an upcoming deadline, such as vblank, by > + * which point the waiter would prefer the fence to be signaled by. This > + * is intended to give feedback to the fence signaler to aid in power > + * management decisions, such as boosting GPU frequency if a periodic > + * vblank deadline is approaching. > + */ > +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline) > +{ > + unsigned long flags; > + > + if (dma_fence_is_signaled(fence)) > + return; > + > + spin_lock_irqsave(fence->lock, flags); > + > + /* If we already have an earlier deadline, keep it: */ > + if (test_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &fence->flags) && > + ktime_before(fence->deadline, deadline)) { > + spin_unlock_irqrestore(fence->lock, flags); > + return; > + } > + > + fence->deadline = deadline; > + set_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT, &fence->flags); > + > + spin_unlock_irqrestore(fence->lock, flags); > + > + if (fence->ops->set_deadline) > + fence->ops->set_deadline(fence, deadline); > +} > +EXPORT_SYMBOL(dma_fence_set_deadline); > + > /** > * dma_fence_init - Initialize a custom fence. > * @fence: the fence to initialize > diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h > index 6ffb4b2c6371..4e6cfe4e6fbc 100644 > --- a/include/linux/dma-fence.h > +++ b/include/linux/dma-fence.h > @@ -88,6 +88,7 @@ struct dma_fence { > /* @timestamp replaced by @rcu on dma_fence_release() */ > struct rcu_head rcu; > }; > + ktime_t deadline; Mhm, adding the flag sounds ok to me but I'm a bit hesitating adding the deadline as extra field here. We tuned the dma_fence structure intentionally so that it is only 64 bytes. Regards, Christian. > u64 context; > u64 seqno; > unsigned long flags; > @@ -99,6 +100,7 @@ enum dma_fence_flag_bits { > DMA_FENCE_FLAG_SIGNALED_BIT, > DMA_FENCE_FLAG_TIMESTAMP_BIT, > DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, > + DMA_FENCE_FLAG_HAS_DEADLINE_BIT, > DMA_FENCE_FLAG_USER_BITS, /* must always be last member */ > }; > > @@ -261,6 +263,19 @@ struct dma_fence_ops { > */ > void (*timeline_value_str)(struct dma_fence *fence, > char *str, int size); > + > + /** > + * @set_deadline: > + * > + * Callback to allow a fence waiter to inform the fence signaler of an > + * upcoming deadline, such as vblank, by which point the waiter would > + * prefer the fence to be signaled by. This is intended to give feedback > + * to the fence signaler to aid in power management decisions, such as > + * boosting GPU frequency. > + * > + * This callback is optional. > + */ > + void (*set_deadline)(struct dma_fence *fence, ktime_t deadline); > }; > > void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, > @@ -586,6 +601,8 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) > return ret < 0 ? ret : 0; > } > > +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline); > + > struct dma_fence *dma_fence_get_stub(void); > struct dma_fence *dma_fence_allocate_private_stub(void); > u64 dma_fence_context_alloc(unsigned num);