From patchwork Thu Dec 17 23:06:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 11980981 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 96365C4361B for ; Thu, 17 Dec 2020 23:07:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 689C823A51 for ; Thu, 17 Dec 2020 23:07:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731489AbgLQXG6 (ORCPT ); Thu, 17 Dec 2020 18:06:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729402AbgLQXG6 (ORCPT ); Thu, 17 Dec 2020 18:06:58 -0500 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F044C061794 for ; Thu, 17 Dec 2020 15:06:18 -0800 (PST) Received: by mail-pg1-x529.google.com with SMTP id n16so142820pgm.0 for ; Thu, 17 Dec 2020 15:06:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=HLdfcjdPBfqUHXsLl2/ctpr8oIlwE7TAUWyEcwHrLdo=; b=I/k40Wchhcm6MZuqEHbwdbTHc/ZYCFhdu3W1pzS+58BhviIvTCTacXeuwFNTqHBCD2 uGrSudanYZYtLKhIKSHVOICqH5rzlWjRg44ftUkEShN1QCpGkKMWyeu+Foo4dYGCDRwq 9zqnN7tYT6PBgf6iNWmpuzmgSdOYJcWsvhO7GMcyJloFyUVwW1TBMsVrrI5KbjNC5UFP ELNhywtVge3Fy6aEdovPNCbO0rTHf8gOm4fRcS6PY8Oj/Atyfj0Gy5ywwpgVJCGlv3rj IdXYkuqc+j2+3UDIc+OiaTjS6yi4cmMJ0rtAtogWyXYPy7BAKEK7L2HizyC1MUiZlfGK mxWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=HLdfcjdPBfqUHXsLl2/ctpr8oIlwE7TAUWyEcwHrLdo=; b=OuCRKL0vRqM/mjm17ju6GYffHlEklMk5QEL3yiEk38RwNiWFQ3oA+DJ0drBTik8AYw RBRLpa3mhIqiHSW9vsH2gV/9kp4qUdsxnS5/jXa7osuOTASokPq8462uUNFQuofBL2Fj GDAiGHPV6fUq/iFupLAEqjGCXKmYVYP+jos3lNZg05Sq+eGJZmg5elgx+0E1gd+NCmlx 4NXdA11RsMxDC+Z0Z2sHB8zn/YOV/p2MQS46206owEx3B2KVt6KJZSF4hzULLkKJU6PB BZJguXCVCDnwkT+sI8h6HoqEbE5jLfe6sDf5+Q8i0xB1k8uP1XgCZ+moAD4HZoc0eudY tLoA== X-Gm-Message-State: AOAM533kZlEYiBGe6p+g6S+bY7/4xHdDpHz4bN3O6Xkns+LS/PqXz7pN 1UIGDhlzOxSt9pPWoN6v+FyZZA== X-Google-Smtp-Source: ABdhPJxlOSq8edo4ebrfmzOkKDhWUI4iNXReB/PECcycuNq3WkAnJfowi52bwLCAHeWjpe+6PDYaZQ== X-Received: by 2002:a63:7407:: with SMTP id p7mr1500682pgc.48.1608246377608; Thu, 17 Dec 2020 15:06:17 -0800 (PST) Received: from localhost.localdomain ([2601:1c2:680:1319:692:26ff:feda:3a81]) by smtp.gmail.com with ESMTPSA id q9sm7074036pgb.82.2020.12.17.15.06.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Dec 2020 15:06:16 -0800 (PST) From: John Stultz To: lkml Cc: John Stultz , Sumit Semwal , Liam Mark , Chris Goldsworthy , Laura Abbott , Brian Starkey , Hridya Valsaraju , Suren Baghdasaryan , Sandeep Patil , Daniel Mentz , =?utf-8?q?=C3=98rjan_Eide?= , Robin Murphy , Ezequiel Garcia , Simon Ser , James Jones , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [RFC][PATCH 1/3] dma-buf: heaps: Add deferred-free-helper library code Date: Thu, 17 Dec 2020 23:06:10 +0000 Message-Id: <20201217230612.32397-1-john.stultz@linaro.org> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This patch provides infrastructure for deferring buffer frees. This is a feature ION provided which when used with some form of a page pool, provides a nice performance boost in an allocation microbenchmark. The reason it helps is it allows the page-zeroing to be done out of the normal allocation/free path, and pushed off to a kthread. As not all heaps will find this useful, its implemented as a optional helper library that heaps can utilize. Cc: Sumit Semwal Cc: Liam Mark Cc: Chris Goldsworthy Cc: Laura Abbott Cc: Brian Starkey Cc: Hridya Valsaraju Cc: Suren Baghdasaryan Cc: Sandeep Patil Cc: Daniel Mentz Cc: Ørjan Eide Cc: Robin Murphy Cc: Ezequiel Garcia Cc: Simon Ser Cc: James Jones Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: John Stultz --- drivers/dma-buf/heaps/Kconfig | 3 + drivers/dma-buf/heaps/Makefile | 1 + drivers/dma-buf/heaps/deferred-free-helper.c | 136 +++++++++++++++++++ drivers/dma-buf/heaps/deferred-free-helper.h | 15 ++ 4 files changed, 155 insertions(+) create mode 100644 drivers/dma-buf/heaps/deferred-free-helper.c create mode 100644 drivers/dma-buf/heaps/deferred-free-helper.h diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index a5eef06c4226..ecf65204f714 100644 --- a/drivers/dma-buf/heaps/Kconfig +++ b/drivers/dma-buf/heaps/Kconfig @@ -1,3 +1,6 @@ +config DMABUF_HEAPS_DEFERRED_FREE + bool + config DMABUF_HEAPS_SYSTEM bool "DMA-BUF System Heap" depends on DMABUF_HEAPS diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile index 974467791032..4e7839875615 100644 --- a/drivers/dma-buf/heaps/Makefile +++ b/drivers/dma-buf/heaps/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_DMABUF_HEAPS_DEFERRED_FREE) += deferred-free-helper.o obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o obj-$(CONFIG_DMABUF_HEAPS_CMA) += cma_heap.o diff --git a/drivers/dma-buf/heaps/deferred-free-helper.c b/drivers/dma-buf/heaps/deferred-free-helper.c new file mode 100644 index 000000000000..b8f54860454f --- /dev/null +++ b/drivers/dma-buf/heaps/deferred-free-helper.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Deferred dmabuf freeing helper + * + * Copyright (C) 2020 Linaro, Ltd. + * + * Based on the ION page pool code + * Copyright (C) 2011 Google, Inc. + */ + +#include +#include +#include +#include +#include + +#include "deferred-free-helper.h" + +static LIST_HEAD(free_list); +static size_t list_size; +wait_queue_head_t freelist_waitqueue; +struct task_struct *freelist_task; +static DEFINE_MUTEX(free_list_lock); + +enum { + USE_POOL = 0, + SKIP_POOL = 1, +}; + +void deferred_free(struct deferred_freelist_item *item, + void (*free)(struct deferred_freelist_item*, bool), + size_t size) +{ + INIT_LIST_HEAD(&item->list); + item->size = size; + item->free = free; + + mutex_lock(&free_list_lock); + list_add(&item->list, &free_list); + list_size += size; + mutex_unlock(&free_list_lock); + wake_up(&freelist_waitqueue); +} + +static size_t free_one_item(bool nopool) +{ + size_t size = 0; + struct deferred_freelist_item *item; + + mutex_lock(&free_list_lock); + if (list_empty(&free_list)) { + mutex_unlock(&free_list_lock); + return 0; + } + item = list_first_entry(&free_list, struct deferred_freelist_item, list); + list_del(&item->list); + size = item->size; + list_size -= size; + mutex_unlock(&free_list_lock); + + item->free(item, nopool); + return size; +} + +static unsigned long get_freelist_size(void) +{ + unsigned long size; + + mutex_lock(&free_list_lock); + size = list_size; + mutex_unlock(&free_list_lock); + return size; +} + +static unsigned long freelist_shrink_count(struct shrinker *shrinker, + struct shrink_control *sc) +{ + return get_freelist_size(); +} + +static unsigned long freelist_shrink_scan(struct shrinker *shrinker, + struct shrink_control *sc) +{ + int total_freed = 0; + + if (sc->nr_to_scan == 0) + return 0; + + while (total_freed < sc->nr_to_scan) { + int freed = free_one_item(SKIP_POOL); + + if (!freed) + break; + + total_freed += freed; + } + + return total_freed; +} + +static struct shrinker freelist_shrinker = { + .count_objects = freelist_shrink_count, + .scan_objects = freelist_shrink_scan, + .seeks = DEFAULT_SEEKS, + .batch = 0, +}; + +static int deferred_free_thread(void *data) +{ + while (true) { + wait_event_freezable(freelist_waitqueue, + get_freelist_size() > 0); + + free_one_item(USE_POOL); + } + + return 0; +} + +static int deferred_freelist_init(void) +{ + list_size = 0; + + init_waitqueue_head(&freelist_waitqueue); + freelist_task = kthread_run(deferred_free_thread, NULL, + "%s", "dmabuf-deferred-free-worker"); + if (IS_ERR(freelist_task)) { + pr_err("%s: creating thread for deferred free failed\n", + __func__); + return -1; + } + sched_set_normal(freelist_task, 19); + + return register_shrinker(&freelist_shrinker); +} +device_initcall(deferred_freelist_init); diff --git a/drivers/dma-buf/heaps/deferred-free-helper.h b/drivers/dma-buf/heaps/deferred-free-helper.h new file mode 100644 index 000000000000..09a2274a897c --- /dev/null +++ b/drivers/dma-buf/heaps/deferred-free-helper.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef DEFERRED_FREE_HELPER_H +#define DEFERRED_FREE_HELPER_H + +struct deferred_freelist_item { + size_t size; + void (*free)(struct deferred_freelist_item *i, bool no_pool); + struct list_head list; +}; + +void deferred_free(struct deferred_freelist_item *item, + void (*free)(struct deferred_freelist_item *i, bool no_pool), + size_t size); +#endif