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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 757A6C433E0 for ; Fri, 12 Mar 2021 21:15:57 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 1553364F89 for ; Fri, 12 Mar 2021 21:15:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1553364F89 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id CCBA643083; Fri, 12 Mar 2021 21:15:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ulc7c5HKqDDl; Fri, 12 Mar 2021 21:15:55 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTP id 7834F414D8; Fri, 12 Mar 2021 21:15:55 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 53797C000B; Fri, 12 Mar 2021 21:15:55 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id B118CC0001 for ; Fri, 12 Mar 2021 21:15:53 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 972584308D for ; Fri, 12 Mar 2021 21:15:53 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id E-_-5PofSnvv for ; Fri, 12 Mar 2021 21:15:52 +0000 (UTC) X-Greylist: delayed 19:31:59 by SQLgrey-1.8.0 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by smtp2.osuosl.org (Postfix) with ESMTPS id 40D77414D8 for ; Fri, 12 Mar 2021 21:15:52 +0000 (UTC) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id E42F588F; Fri, 12 Mar 2021 22:15:45 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1615583748; bh=p8ueHT9hBdjrMPYv+MNwpSukqWWphQpzWFHWfs4obWw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ALfevHDTrqstjtEeufaD30QjSQve50uup68letkVC4uQxPj7cVqO5KT3DRpP3TdzZ MyPx0dq/9Jx5+TQLrUYyC6jmpRk3nLVlocJG6DCHomcfKJCNbHLkh5FXvjLvpfx08V Ew9T+yE5q2GJItOt27mAspmiE7CiRDW4Sgq1Hyio= Date: Fri, 12 Mar 2021 23:15:03 +0200 From: Laurent Pinchart To: Ricardo Ribalda Subject: Re: [PATCH v2 6/6] media: uvcvideo: Use dma_alloc_noncontiguous API Message-ID: References: <20210312125709.1347177-1-ribalda@chromium.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210312125709.1347177-1-ribalda@chromium.org> Cc: Sergey Senozhatsky , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Mauro Carvalho Chehab , Robin Murphy , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Ricardo, Thank you for the patch. On Fri, Mar 12, 2021 at 01:57:09PM +0100, Ricardo Ribalda wrote: > On architectures where there is no coherent caching such as ARM use the > dma_alloc_noncontiguous API and handle manually the cache flushing using > dma_sync_sgtable(). You're actually switching to dma_alloc_noncontiguous() unconditionally, not only on those architectures :-) Do I assume correctly that dma_alloc_noncontiguous() will do the right thing on x86 too ? > With this patch on the affected architectures we can measure up to 20x > performance improvement in uvc_video_copy_data_work(). Have you measured performances on x86 to ensure there's no regression ? > Eg: aarch64 with an external usb camera > > NON_CONTIGUOUS > frames: 999 > packets: 999 > empty: 0 (0 %) > errors: 0 > invalid: 0 > pts: 0 early, 0 initial, 999 ok > scr: 0 count ok, 0 diff ok > sof: 2048 <= sof <= 0, freq 0.000 kHz > bytes 67034480 : duration 33303 > FPS: 29.99 > URB: 523446/4993 uS/qty: 104.836 avg 132.532 std 13.230 min 831.094 max (uS) > header: 76564/4993 uS/qty: 15.334 avg 15.229 std 3.438 min 186.875 max (uS) > latency: 468945/4992 uS/qty: 93.939 avg 132.577 std 9.531 min 824.010 max (uS) > decode: 54161/4993 uS/qty: 10.847 avg 6.313 std 1.614 min 111.458 max (uS) > raw decode speed: 9.931 Gbits/s > raw URB handling speed: 1.025 Gbits/s > throughput: 16.102 Mbits/s > URB decode CPU usage 0.162600 % > > COHERENT > frames: 999 > packets: 999 > empty: 0 (0 %) > errors: 0 > invalid: 0 > pts: 0 early, 0 initial, 999 ok > scr: 0 count ok, 0 diff ok > sof: 2048 <= sof <= 0, freq 0.000 kHz > bytes 54683536 : duration 33302 > FPS: 29.99 > URB: 1478135/4000 uS/qty: 369.533 avg 390.357 std 22.968 min 3337.865 max (uS) > header: 79761/4000 uS/qty: 19.940 avg 18.495 std 1.875 min 336.719 max (uS) > latency: 281077/4000 uS/qty: 70.269 avg 83.102 std 5.104 min 735.000 max (uS) > decode: 1197057/4000 uS/qty: 299.264 avg 318.080 std 1.615 min 2806.667 max (uS) > raw decode speed: 365.470 Mbits/s > raw URB handling speed: 295.986 Mbits/s > throughput: 13.136 Mbits/s > URB decode CPU usage 3.594500 % > > Signed-off-by: Ricardo Ribalda > Reviewed-by: Tomasz Figa > Signed-off-by: Christoph Hellwig > --- > > Changelog from v2: (Thanks Laurent) > > - Fix typos > - Use the right dma direction if not capturing > - Clear sgt during free > > drivers/media/usb/uvc/uvc_video.c | 92 +++++++++++++++++++++++-------- > drivers/media/usb/uvc/uvcvideo.h | 5 +- > 2 files changed, 74 insertions(+), 23 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index f2f565281e63..8e60f81e2257 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -6,11 +6,14 @@ > * Laurent Pinchart (laurent.pinchart@ideasonboard.com) > */ > > +#include > +#include > #include > #include > #include > #include > #include > +#include > #include > #include > #include > @@ -1096,6 +1099,34 @@ static int uvc_video_decode_start(struct uvc_streaming *stream, > return data[0]; > } > > +static inline enum dma_data_direction stream_dir(struct uvc_streaming *stream) > +{ > + if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) > + return DMA_FROM_DEVICE; > + else > + return DMA_TO_DEVICE; > +} > + > +static inline struct device *stream_to_dmadev(struct uvc_streaming *stream) > +{ > + return bus_to_hcd(stream->dev->udev->bus)->self.sysdev; > +} > + > +static void uvc_urb_dma_sync(struct uvc_urb *uvc_urb, bool for_device) Maybe nitpicking a little bit, but wouldn't the code be clearer if you created uvc_urb_dma_sync_for_cpu() and uvc_urb_dma_sync_for_device() ? When reading uvc_urb_dma_sync(uvc_urb, true); I have to constantly look up the definition of the function to figure out what boolean value corresponds to what direction. Given that uvc_urb_dma_sync(..., true) is always called right before submitting the URB, we could even create a uvc_submit_urb() function that groups the dma_sync_sgtable_for_device() and usb_submit_urb() calls, and do without uvc_urb_dma_sync_for_device(). Up to you on this one. With those small changes, and assuming there's no performance regression on x86, Reviewed-by: Laurent Pinchart > +{ > + struct device *dma_dev = stream_to_dmadev(uvc_urb->stream); > + > + if (for_device) { > + dma_sync_sgtable_for_device(dma_dev, uvc_urb->sgt, > + stream_dir(uvc_urb->stream)); > + } else { > + dma_sync_sgtable_for_cpu(dma_dev, uvc_urb->sgt, > + stream_dir(uvc_urb->stream)); > + invalidate_kernel_vmap_range(uvc_urb->buffer, > + uvc_urb->stream->urb_size); > + } > +} > + > /* > * uvc_video_decode_data_work: Asynchronous memcpy processing > * > @@ -1117,6 +1148,8 @@ static void uvc_video_copy_data_work(struct work_struct *work) > uvc_queue_buffer_release(op->buf); > } > > + uvc_urb_dma_sync(uvc_urb, true); > + > ret = usb_submit_urb(uvc_urb->urb, GFP_KERNEL); > if (ret < 0) > dev_err(&uvc_urb->stream->intf->dev, > @@ -1541,10 +1574,12 @@ static void uvc_video_complete(struct urb *urb) > * Process the URB headers, and optionally queue expensive memcpy tasks > * to be deferred to a work queue. > */ > + uvc_urb_dma_sync(uvc_urb, false); > stream->decode(uvc_urb, buf, buf_meta); > > /* If no async work is needed, resubmit the URB immediately. */ > if (!uvc_urb->async_operations) { > + uvc_urb_dma_sync(uvc_urb, true); > ret = usb_submit_urb(uvc_urb->urb, GFP_ATOMIC); > if (ret < 0) > dev_err(&stream->intf->dev, > @@ -1560,24 +1595,49 @@ static void uvc_video_complete(struct urb *urb) > */ > static void uvc_free_urb_buffers(struct uvc_streaming *stream) > { > + struct device *dma_dev = stream_to_dmadev(stream); > struct uvc_urb *uvc_urb; > > for_each_uvc_urb(uvc_urb, stream) { > if (!uvc_urb->buffer) > continue; > > -#ifndef CONFIG_DMA_NONCOHERENT > - usb_free_coherent(stream->dev->udev, stream->urb_size, > - uvc_urb->buffer, uvc_urb->dma); > -#else > - kfree(uvc_urb->buffer); > -#endif > + dma_vunmap_noncontiguous(dma_dev, uvc_urb->buffer); > + dma_free_noncontiguous(dma_dev, stream->urb_size, uvc_urb->sgt, > + stream_dir(stream)); > + > uvc_urb->buffer = NULL; > + uvc_urb->sgt = NULL; > } > > stream->urb_size = 0; > } > > +static bool uvc_alloc_urb_buffer(struct uvc_streaming *stream, > + struct uvc_urb *uvc_urb, gfp_t gfp_flags) > +{ > + struct device *dma_dev = stream_to_dmadev(stream); > + > + uvc_urb->sgt = dma_alloc_noncontiguous(dma_dev, stream->urb_size, > + stream_dir(stream), > + gfp_flags, 0); > + if (!uvc_urb->sgt) > + return false; > + uvc_urb->dma = uvc_urb->sgt->sgl->dma_address; > + > + uvc_urb->buffer = dma_vmap_noncontiguous(dma_dev, stream->urb_size, > + uvc_urb->sgt); > + if (!uvc_urb->buffer) { > + dma_free_noncontiguous(dma_dev, stream->urb_size, > + uvc_urb->sgt, > + stream_dir(stream)); > + uvc_urb->sgt = NULL; > + return false; > + } > + > + return true; > +} > + > /* > * Allocate transfer buffers. This function can be called with buffers > * already allocated when resuming from suspend, in which case it will > @@ -1608,19 +1668,12 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream, > > /* Retry allocations until one succeed. */ > for (; npackets > 1; npackets /= 2) { > + stream->urb_size = psize * npackets; > + > for (i = 0; i < UVC_URBS; ++i) { > struct uvc_urb *uvc_urb = &stream->uvc_urb[i]; > > - stream->urb_size = psize * npackets; > -#ifndef CONFIG_DMA_NONCOHERENT > - uvc_urb->buffer = usb_alloc_coherent( > - stream->dev->udev, stream->urb_size, > - gfp_flags | __GFP_NOWARN, &uvc_urb->dma); > -#else > - uvc_urb->buffer = > - kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN); > -#endif > - if (!uvc_urb->buffer) { > + if (!uvc_alloc_urb_buffer(stream, uvc_urb, gfp_flags)) { > uvc_free_urb_buffers(stream); > break; > } > @@ -1730,12 +1783,8 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream, > urb->context = uvc_urb; > urb->pipe = usb_rcvisocpipe(stream->dev->udev, > ep->desc.bEndpointAddress); > -#ifndef CONFIG_DMA_NONCOHERENT > urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; > urb->transfer_dma = uvc_urb->dma; > -#else > - urb->transfer_flags = URB_ISO_ASAP; > -#endif > urb->interval = ep->desc.bInterval; > urb->transfer_buffer = uvc_urb->buffer; > urb->complete = uvc_video_complete; > @@ -1795,10 +1844,8 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream, > > usb_fill_bulk_urb(urb, stream->dev->udev, pipe, uvc_urb->buffer, > size, uvc_video_complete, uvc_urb); > -#ifndef CONFIG_DMA_NONCOHERENT > urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; > urb->transfer_dma = uvc_urb->dma; > -#endif > > uvc_urb->urb = urb; > } > @@ -1895,6 +1942,7 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, > > /* Submit the URBs. */ > for_each_uvc_urb(uvc_urb, stream) { > + uvc_urb_dma_sync(uvc_urb, true); > ret = usb_submit_urb(uvc_urb->urb, gfp_flags); > if (ret < 0) { > dev_err(&stream->intf->dev, > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > index 97df5ecd66c9..cce5e38133cd 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -219,6 +219,7 @@ > */ > > struct gpio_desc; > +struct sg_table; > struct uvc_device; > > /* TODO: Put the most frequently accessed fields at the beginning of > @@ -545,7 +546,8 @@ struct uvc_copy_op { > * @urb: the URB described by this context structure > * @stream: UVC streaming context > * @buffer: memory storage for the URB > - * @dma: DMA coherent addressing for the urb_buffer > + * @dma: Allocated DMA handle > + * @sgt: sgt_table with the urb locations in memory > * @async_operations: counter to indicate the number of copy operations > * @copy_operations: work descriptors for asynchronous copy operations > * @work: work queue entry for asynchronous decode > @@ -556,6 +558,7 @@ struct uvc_urb { > > char *buffer; > dma_addr_t dma; > + struct sg_table *sgt; > > unsigned int async_operations; > struct uvc_copy_op copy_operations[UVC_MAX_PACKETS]; -- Regards, Laurent Pinchart _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu