From patchwork Tue Jul 13 04:07:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hridya Valsaraju X-Patchwork-Id: 75726 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1m39iJ-005AYS-Hb; Tue, 13 Jul 2021 04:08:08 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229449AbhGMEKj (ORCPT + 1 other); Tue, 13 Jul 2021 00:10:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbhGMEKj (ORCPT ); Tue, 13 Jul 2021 00:10:39 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1012C0613DD for ; Mon, 12 Jul 2021 21:07:49 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id x84-20020a2531570000b029055d47682463so23892099ybx.5 for ; Mon, 12 Jul 2021 21:07:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc :content-transfer-encoding; bh=lsRQcYOnLNGeZNFv9ZqabeUiQqK2KSkzul/BCImYOGQ=; b=gPSXuiokMiiFcRSzhrt4fHhIbGRoeQi7Eq4XA3gKVm2B6yAWrkdk1rCOxk5ky642fW 8EHwZOyTerEb18XV86OudV9UyVF5PNC3+cN/Owf5gp3iAAtyiQpPC5juqs2nfmbNcZNp G9iSIfJn0IcLbJvo+qX+4b97x+ytRKUmB707yHZX0a4Ugkbu3BPyzJYBscBtOIlr+9PZ 4s9qPHYX8K2TTwoSRiEs7/l7fbu7mjOlJKvImJQMMIhMInUcVqAKkbHhqySlvBw1V/Aw MnhDQH+dkssXHH6sEZFKpPcBmVs1Td2epMkxH7yfPTDg8blpTOoYfNx8z26aFc+hNMe5 iBHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc :content-transfer-encoding; bh=lsRQcYOnLNGeZNFv9ZqabeUiQqK2KSkzul/BCImYOGQ=; b=B4XZW2yV4Vj6tnP+4GHpQai9xaiiBWQkJ/j5tBWVvYbzlDPvpfUck2DlS5uoQp3uBu gQKT41bDRpeAg3YPyeHThKAnSq6/LLWtWVo7x3M4Coxypo4Mkqrk9Df4ZLoOEnAwjDjZ SpywBWxZR7N1QYqU6zVR9RnB6esakNufKKJNPk/r+vQpgERiLXObQwUPSFSVbGbCuUOL U9eDJ+y3ps9GvWf7b58pwLSW1sOlsbdMTkxVyqkfCngc676mLBjFPpdNvX2US0LJz1Gh 5ozb2PimDI3i3EYi0M5qpeYt0gvoyzvnTclEzZEaV0sJBs6jfpdShoneTBL07Nd9Ar/1 byWw== X-Gm-Message-State: AOAM532gCktrT5EOjy20AfR9itL1praAs6WSMcOtV3Uyldqn76KTpXuC SKC94Vi2TdjazMUbCil/8hPzIALBB0s= X-Google-Smtp-Source: ABdhPJxZMjSGTD6Q9sj/OJwUJwZToli5AFricGI0zhixsoa2+/EbM8Q8aIAn6TH/hNqolerSh4FEQ1DfqVs= X-Received: from hridya.mtv.corp.google.com ([2620:15c:211:200:2156:3303:4d7a:cc35]) (user=hridya job=sendgmr) by 2002:a5b:c0a:: with SMTP id f10mr3006444ybq.9.1626149269053; Mon, 12 Jul 2021 21:07:49 -0700 (PDT) Date: Mon, 12 Jul 2021 21:07:38 -0700 Message-Id: <20210713040742.2680135-1-hridya@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.32.0.93.g670b81a890-goog Subject: [PATCH v2] dma-buf: Delete the DMA-BUF attachment sysfs statistics From: Hridya Valsaraju To: christian.koenig@amd.com, Sumit Semwal , Hridya Valsaraju , Greg Kroah-Hartman , Daniel Vetter , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org Cc: kernel-team@android.com, john.stultz@linaro.org, surenb@google.com, daniel@ffwll.ch Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -10.0 (----------) X-LSpam-Report: No, score=-10.0 required=5.0 tests=BAYES_00=-1.9,DKIMWL_WL_MED=0.001,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1,RCVD_IN_DNSWL_NONE=-0.0001,USER_IN_DEF_DKIM_WL=-7.5 autolearn=ham autolearn_force=no The DMA-BUF attachment statistics form a subset of the DMA-BUF sysfs statistics that recently merged to the drm-misc tree. They are not UABI yet since they have not merged to the upstream Linux kernel. Since there has been a reported a performance regression due to the overhead of sysfs directory creation/teardown during dma_buf_attach()/dma_buf_detach(), this patch deletes the DMA-BUF attachment statistics from sysfs. Fixes: bdb8d06dfefd (dmabuf: Add the capability to expose DMA-BUF stats in sysfs) Signed-off-by: Hridya Valsaraju Reviewed-by: Christian König Reviewed-by: Greg Kroah-Hartman --- Changes in v2: Updated commit message to clarify that the sysfs files being removed have not yet merged to upstream Linux and are hence not ABI. Hi Christian, I have updated the commit message as per your suggestion. Please do take another look when you get a chance. Thanks, Hridya .../ABI/testing/sysfs-kernel-dmabuf-buffers | 28 ---- drivers/dma-buf/dma-buf-sysfs-stats.c | 140 +----------------- drivers/dma-buf/dma-buf-sysfs-stats.h | 27 ---- drivers/dma-buf/dma-buf.c | 16 -- include/linux/dma-buf.h | 17 --- 5 files changed, 4 insertions(+), 224 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers index a243984ed420..5d3bc997dc64 100644 --- a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers +++ b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers @@ -22,31 +22,3 @@ KernelVersion: v5.13 Contact: Hridya Valsaraju Description: This file is read-only and specifies the size of the DMA-BUF in bytes. - -What: /sys/kernel/dmabuf/buffers//attachments -Date: May 2021 -KernelVersion: v5.13 -Contact: Hridya Valsaraju -Description: This directory will contain subdirectories representing every - attachment of the DMA-BUF. - -What: /sys/kernel/dmabuf/buffers//attachments/ -Date: May 2021 -KernelVersion: v5.13 -Contact: Hridya Valsaraju -Description: This directory will contain information on the attached device - and the number of current distinct device mappings. - -What: /sys/kernel/dmabuf/buffers//attachments//device -Date: May 2021 -KernelVersion: v5.13 -Contact: Hridya Valsaraju -Description: This file is read-only and is a symlink to the attached device's - sysfs entry. - -What: /sys/kernel/dmabuf/buffers//attachments//map_counter -Date: May 2021 -KernelVersion: v5.13 -Contact: Hridya Valsaraju -Description: This file is read-only and contains a map_counter indicating the - number of distinct device mappings of the attachment. diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c index a2638e84199c..053baadcada9 100644 --- a/drivers/dma-buf/dma-buf-sysfs-stats.c +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c @@ -40,14 +40,11 @@ * * * ``/sys/kernel/dmabuf/buffers//exporter_name`` * * ``/sys/kernel/dmabuf/buffers//size`` - * * ``/sys/kernel/dmabuf/buffers//attachments//device`` - * * ``/sys/kernel/dmabuf/buffers//attachments//map_counter`` * - * The information in the interface can also be used to derive per-exporter and - * per-device usage statistics. The data from the interface can be gathered - * on error conditions or other important events to provide a snapshot of - * DMA-BUF usage. It can also be collected periodically by telemetry to monitor - * various metrics. + * The information in the interface can also be used to derive per-exporter + * statistics. The data from the interface can be gathered on error conditions + * or other important events to provide a snapshot of DMA-BUF usage. + * It can also be collected periodically by telemetry to monitor various metrics. * * Detailed documentation about the interface is present in * Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers. @@ -121,120 +118,6 @@ static struct kobj_type dma_buf_ktype = { .default_groups = dma_buf_stats_default_groups, }; -#define to_dma_buf_attach_entry_from_kobj(x) container_of(x, struct dma_buf_attach_sysfs_entry, kobj) - -struct dma_buf_attach_stats_attribute { - struct attribute attr; - ssize_t (*show)(struct dma_buf_attach_sysfs_entry *sysfs_entry, - struct dma_buf_attach_stats_attribute *attr, char *buf); -}; -#define to_dma_buf_attach_stats_attr(x) container_of(x, struct dma_buf_attach_stats_attribute, attr) - -static ssize_t dma_buf_attach_stats_attribute_show(struct kobject *kobj, - struct attribute *attr, - char *buf) -{ - struct dma_buf_attach_stats_attribute *attribute; - struct dma_buf_attach_sysfs_entry *sysfs_entry; - - attribute = to_dma_buf_attach_stats_attr(attr); - sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); - - if (!attribute->show) - return -EIO; - - return attribute->show(sysfs_entry, attribute, buf); -} - -static const struct sysfs_ops dma_buf_attach_stats_sysfs_ops = { - .show = dma_buf_attach_stats_attribute_show, -}; - -static ssize_t map_counter_show(struct dma_buf_attach_sysfs_entry *sysfs_entry, - struct dma_buf_attach_stats_attribute *attr, - char *buf) -{ - return sysfs_emit(buf, "%u\n", sysfs_entry->map_counter); -} - -static struct dma_buf_attach_stats_attribute map_counter_attribute = - __ATTR_RO(map_counter); - -static struct attribute *dma_buf_attach_stats_default_attrs[] = { - &map_counter_attribute.attr, - NULL, -}; -ATTRIBUTE_GROUPS(dma_buf_attach_stats_default); - -static void dma_buf_attach_sysfs_release(struct kobject *kobj) -{ - struct dma_buf_attach_sysfs_entry *sysfs_entry; - - sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); - kfree(sysfs_entry); -} - -static struct kobj_type dma_buf_attach_ktype = { - .sysfs_ops = &dma_buf_attach_stats_sysfs_ops, - .release = dma_buf_attach_sysfs_release, - .default_groups = dma_buf_attach_stats_default_groups, -}; - -void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) -{ - struct dma_buf_attach_sysfs_entry *sysfs_entry; - - sysfs_entry = attach->sysfs_entry; - if (!sysfs_entry) - return; - - sysfs_delete_link(&sysfs_entry->kobj, &attach->dev->kobj, "device"); - - kobject_del(&sysfs_entry->kobj); - kobject_put(&sysfs_entry->kobj); -} - -int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, - unsigned int uid) -{ - struct dma_buf_attach_sysfs_entry *sysfs_entry; - int ret; - struct dma_buf *dmabuf; - - if (!attach) - return -EINVAL; - - dmabuf = attach->dmabuf; - - sysfs_entry = kzalloc(sizeof(struct dma_buf_attach_sysfs_entry), - GFP_KERNEL); - if (!sysfs_entry) - return -ENOMEM; - - sysfs_entry->kobj.kset = dmabuf->sysfs_entry->attach_stats_kset; - - attach->sysfs_entry = sysfs_entry; - - ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_attach_ktype, - NULL, "%u", uid); - if (ret) - goto kobj_err; - - ret = sysfs_create_link(&sysfs_entry->kobj, &attach->dev->kobj, - "device"); - if (ret) - goto link_err; - - return 0; - -link_err: - kobject_del(&sysfs_entry->kobj); -kobj_err: - kobject_put(&sysfs_entry->kobj); - attach->sysfs_entry = NULL; - - return ret; -} void dma_buf_stats_teardown(struct dma_buf *dmabuf) { struct dma_buf_sysfs_entry *sysfs_entry; @@ -243,7 +126,6 @@ void dma_buf_stats_teardown(struct dma_buf *dmabuf) if (!sysfs_entry) return; - kset_unregister(sysfs_entry->attach_stats_kset); kobject_del(&sysfs_entry->kobj); kobject_put(&sysfs_entry->kobj); } @@ -290,7 +172,6 @@ int dma_buf_stats_setup(struct dma_buf *dmabuf) { struct dma_buf_sysfs_entry *sysfs_entry; int ret; - struct kset *attach_stats_kset; if (!dmabuf || !dmabuf->file) return -EINVAL; @@ -315,21 +196,8 @@ int dma_buf_stats_setup(struct dma_buf *dmabuf) if (ret) goto err_sysfs_dmabuf; - /* create the directory for attachment stats */ - attach_stats_kset = kset_create_and_add("attachments", - &dmabuf_sysfs_no_uevent_ops, - &sysfs_entry->kobj); - if (!attach_stats_kset) { - ret = -ENOMEM; - goto err_sysfs_attach; - } - - sysfs_entry->attach_stats_kset = attach_stats_kset; - return 0; -err_sysfs_attach: - kobject_del(&sysfs_entry->kobj); err_sysfs_dmabuf: kobject_put(&sysfs_entry->kobj); dmabuf->sysfs_entry = NULL; diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.h b/drivers/dma-buf/dma-buf-sysfs-stats.h index 5f4703249117..a49c6e2650cc 100644 --- a/drivers/dma-buf/dma-buf-sysfs-stats.h +++ b/drivers/dma-buf/dma-buf-sysfs-stats.h @@ -14,23 +14,8 @@ int dma_buf_init_sysfs_statistics(void); void dma_buf_uninit_sysfs_statistics(void); int dma_buf_stats_setup(struct dma_buf *dmabuf); -int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, - unsigned int uid); -static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, - int delta) -{ - struct dma_buf_attach_sysfs_entry *entry = attach->sysfs_entry; - entry->map_counter += delta; -} void dma_buf_stats_teardown(struct dma_buf *dmabuf); -void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach); -static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) -{ - struct dma_buf_sysfs_entry *entry = dmabuf->sysfs_entry; - - return entry->attachment_uid++; -} #else static inline int dma_buf_init_sysfs_statistics(void) @@ -44,19 +29,7 @@ static inline int dma_buf_stats_setup(struct dma_buf *dmabuf) { return 0; } -static inline int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, - unsigned int uid) -{ - return 0; -} static inline void dma_buf_stats_teardown(struct dma_buf *dmabuf) {} -static inline void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) {} -static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, - int delta) {} -static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) -{ - return 0; -} #endif #endif // _DMA_BUF_SYSFS_STATS_H diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 510b42771974..b1a6db71c656 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -738,7 +738,6 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, { struct dma_buf_attachment *attach; int ret; - unsigned int attach_uid; if (WARN_ON(!dmabuf || !dev)) return ERR_PTR(-EINVAL); @@ -764,13 +763,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, } dma_resv_lock(dmabuf->resv, NULL); list_add(&attach->node, &dmabuf->attachments); - attach_uid = dma_buf_update_attach_uid(dmabuf); dma_resv_unlock(dmabuf->resv); - ret = dma_buf_attach_stats_setup(attach, attach_uid); - if (ret) - goto err_sysfs; - /* When either the importer or the exporter can't handle dynamic * mappings we cache the mapping here to avoid issues with the * reservation object lock. @@ -797,7 +791,6 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, dma_resv_unlock(attach->dmabuf->resv); attach->sgt = sgt; attach->dir = DMA_BIDIRECTIONAL; - dma_buf_update_attachment_map_count(attach, 1 /* delta */); } return attach; @@ -814,7 +807,6 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, if (dma_buf_is_dynamic(attach->dmabuf)) dma_resv_unlock(attach->dmabuf->resv); -err_sysfs: dma_buf_detach(dmabuf, attach); return ERR_PTR(ret); } @@ -864,7 +856,6 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) dma_resv_lock(attach->dmabuf->resv, NULL); __unmap_dma_buf(attach, attach->sgt, attach->dir); - dma_buf_update_attachment_map_count(attach, -1 /* delta */); if (dma_buf_is_dynamic(attach->dmabuf)) { dmabuf->ops->unpin(attach); @@ -878,7 +869,6 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach); - dma_buf_attach_stats_teardown(attach); kfree(attach); } EXPORT_SYMBOL_GPL(dma_buf_detach); @@ -1020,10 +1010,6 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, } } #endif /* CONFIG_DMA_API_DEBUG */ - - if (!IS_ERR(sg_table)) - dma_buf_update_attachment_map_count(attach, 1 /* delta */); - return sg_table; } EXPORT_SYMBOL_GPL(dma_buf_map_attachment); @@ -1061,8 +1047,6 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (dma_buf_is_dynamic(attach->dmabuf) && !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) dma_buf_unpin(attach); - - dma_buf_update_attachment_map_count(attach, -1 /* delta */); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 2b814fde0d11..678b2006be78 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -444,15 +444,6 @@ struct dma_buf { struct dma_buf_sysfs_entry { struct kobject kobj; struct dma_buf *dmabuf; - - /** - * @sysfs_entry.attachment_uid: - * - * This is protected by the dma_resv_lock() on @resv and is - * incremented on each attach. - */ - unsigned int attachment_uid; - struct kset *attach_stats_kset; } *sysfs_entry; #endif }; @@ -504,7 +495,6 @@ struct dma_buf_attach_ops { * @importer_ops: importer operations for this attachment, if provided * dma_buf_map/unmap_attachment() must be called with the dma_resv lock held. * @importer_priv: importer specific attachment data. - * @sysfs_entry: For exposing information about this attachment in sysfs. * * This structure holds the attachment information between the dma_buf buffer * and its user device(s). The list contains one attachment struct per device @@ -525,13 +515,6 @@ struct dma_buf_attachment { const struct dma_buf_attach_ops *importer_ops; void *importer_priv; void *priv; -#ifdef CONFIG_DMABUF_SYSFS_STATS - /* for sysfs stats */ - struct dma_buf_attach_sysfs_entry { - struct kobject kobj; - unsigned int map_counter; - } *sysfs_entry; -#endif }; /**