From patchwork Mon Mar 3 19:08:45 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Adrian Larumbe X-Patchwork-Id: 13999366 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 5B737C282C6 for ; Mon, 3 Mar 2025 19:10:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DA35A10E486; Mon, 3 Mar 2025 19:10:15 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=collabora.com header.i=adrian.larumbe@collabora.com header.b="d1mmUFuY"; dkim-atps=neutral Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) by gabe.freedesktop.org (Postfix) with ESMTPS id BC88A10E486 for ; Mon, 3 Mar 2025 19:10:08 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; t=1741028997; cv=none; d=zohomail.com; s=zohoarc; b=enqQTsUYQQxPkqjyvGXFaXPyKtm3bW2Vw9YwAFtXIM7bV/+zQD9qclR4nryMtqfCWVEUfppTOqixbfXNohNRV5ERI9/OOwQSSXbD4vYlKW59xxqSKZetkdgzmLREXmP5p6FUElDg+zH1PhDKh7h4vM8G1Mw8nDtlp2E3CdJ+xFI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1741028997; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=79EEq7MORaFKGZQS0e0YLJcDbCdzpAcNRQ48gbyQtz0=; b=dQkPQnkVqkY9cy+D3H7VkA/uELGBuR1kKksxWMG6D5ejF58V9TGMYT9Biue+3myJNZpoOqSiLsOj4eHQCtuscRIqtVOmJTXUW6Hgd0fA2t8vdzIR4HNyZb3WWuw7MXCyA6SBjlqeiH6SqWMB2xRidxRCi9evTQziKRXQ7ELh1TA= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=adrian.larumbe@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1741028997; s=zohomail; d=collabora.com; i=adrian.larumbe@collabora.com; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=79EEq7MORaFKGZQS0e0YLJcDbCdzpAcNRQ48gbyQtz0=; b=d1mmUFuYH+G3X4MbNOHcxlSCq5+THv3xRXcEkHVB/GrGweEgMsUcui5kS9vpP90R 9fU+seUWCTsDAP0fpRc78XAmr7p0Pcfh3j9DGm3nugWPbeTGozSxIJosZj3yHZvsuum 8NEb+IaasptSQckzRFptdh+upY/dI4sJfvlmOXQk= Received: by mx.zohomail.com with SMTPS id 1741028995020517.922490709406; Mon, 3 Mar 2025 11:09:55 -0800 (PST) From: =?utf-8?q?Adri=C3=A1n_Larumbe?= To: Boris Brezillon , Steven Price , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , =?utf-8?q?Adri=C3=A1n_Larumbe?= Cc: kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 1/2] drm/panthor: Replace sleep locks with spinlocks in fdinfo path Date: Mon, 3 Mar 2025 19:08:45 +0000 Message-ID: <20250303190923.1639985-1-adrian.larumbe@collabora.com> X-Mailer: git-send-email 2.47.1 MIME-Version: 1.0 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Commit 0590c94c3596 ("drm/panthor: Fix race condition when gathering fdinfo group samples") introduced an xarray lock to deal with potential use-after-free errors when accessing groups fdinfo figures. However, this toggles the kernel's atomic context status, so the next nested mutex lock will raise a warning when the kernel is compiled with mutex debug options: CONFIG_DEBUG_RT_MUTEXES=y CONFIG_DEBUG_MUTEXES=y Replace Panthor's group fdinfo data mutex with a guarded spinlock. Signed-off-by: Adrián Larumbe Fixes: 0590c94c3596 ("drm/panthor: Fix race condition when gathering fdinfo group samples") Reviewed-by: Liviu Dudau Reviewed-by: Boris Brezillon Reviewed-by: Steven Price --- drivers/gpu/drm/panthor/panthor_sched.c | 26 ++++++++++++------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c index 1a276db095ff..4d31d1967716 100644 --- a/drivers/gpu/drm/panthor/panthor_sched.c +++ b/drivers/gpu/drm/panthor/panthor_sched.c @@ -9,6 +9,7 @@ #include #include +#include #include #include #include @@ -631,10 +632,10 @@ struct panthor_group { struct panthor_gpu_usage data; /** - * @lock: Mutex to govern concurrent access from drm file's fdinfo callback - * and job post-completion processing function + * @fdinfo.lock: Spinlock to govern concurrent access from drm file's fdinfo + * callback and job post-completion processing function */ - struct mutex lock; + spinlock_t lock; /** @fdinfo.kbo_sizes: Aggregate size of private kernel BO's held by the group. */ size_t kbo_sizes; @@ -910,8 +911,6 @@ static void group_release_work(struct work_struct *work) release_work); u32 i; - mutex_destroy(&group->fdinfo.lock); - for (i = 0; i < group->queue_count; i++) group_free_queue(group, group->queues[i]); @@ -2861,12 +2860,12 @@ static void update_fdinfo_stats(struct panthor_job *job) struct panthor_job_profiling_data *slots = queue->profiling.slots->kmap; struct panthor_job_profiling_data *data = &slots[job->profiling.slot]; - mutex_lock(&group->fdinfo.lock); - if (job->profiling.mask & PANTHOR_DEVICE_PROFILING_CYCLES) - fdinfo->cycles += data->cycles.after - data->cycles.before; - if (job->profiling.mask & PANTHOR_DEVICE_PROFILING_TIMESTAMP) - fdinfo->time += data->time.after - data->time.before; - mutex_unlock(&group->fdinfo.lock); + scoped_guard(spinlock, &group->fdinfo.lock) { + if (job->profiling.mask & PANTHOR_DEVICE_PROFILING_CYCLES) + fdinfo->cycles += data->cycles.after - data->cycles.before; + if (job->profiling.mask & PANTHOR_DEVICE_PROFILING_TIMESTAMP) + fdinfo->time += data->time.after - data->time.before; + } } void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile) @@ -2880,12 +2879,11 @@ void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile) xa_lock(&gpool->xa); xa_for_each(&gpool->xa, i, group) { - mutex_lock(&group->fdinfo.lock); + guard(spinlock)(&group->fdinfo.lock); pfile->stats.cycles += group->fdinfo.data.cycles; pfile->stats.time += group->fdinfo.data.time; group->fdinfo.data.cycles = 0; group->fdinfo.data.time = 0; - mutex_unlock(&group->fdinfo.lock); } xa_unlock(&gpool->xa); } @@ -3537,7 +3535,7 @@ int panthor_group_create(struct panthor_file *pfile, mutex_unlock(&sched->reset.lock); add_group_kbo_sizes(group->ptdev, group); - mutex_init(&group->fdinfo.lock); + spin_lock_init(&group->fdinfo.lock); return gid;