From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFF1028368 for ; Wed, 15 Nov 2023 20:49:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="my9mBFt2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6DFF3C32788; Wed, 15 Nov 2023 20:49:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700081348; bh=dkiv9gmqdG/Gi4Cmz4UB9t/jqtcMzabDUime5IgM6Bs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=my9mBFt2BCRLcUVCuF+A4d0U2oiqgXtX7/TFmrXwCcL1V+nXfUX3iO3499YH3cuzM pW2aEtVSFTP+wYG0aDpcHI9ZR7PpDfpd+bxojPXWHsiiCvLr3KwpR9VAUTZOR5MICc hrOT4altEWsld07ia8R3gehPaDT7yuhO9uT0f5Rk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Xiaogang.Chen" , Felix Kuehling , Alex Deucher , Sasha Levin Subject: [PATCH 5.15 098/244] drm/amdkfd: fix some race conditions in vram buffer alloc/free of svm code Date: Wed, 15 Nov 2023 15:34:50 -0500 Message-ID: <20231115203554.233473364@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115203548.387164783@linuxfoundation.org> References: <20231115203548.387164783@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xiaogang Chen [ Upstream commit 7bfaa160caed8192f8262c4638f552cad94bcf5a ] This patch fixes: 1: ref number of prange's svm_bo got decreased by an async call from hmm. When wait svm_bo of prange got released we shoul also wait prang->svm_bo become NULL, otherwise prange->svm_bo may be set to null after allocate new vram buffer. 2: During waiting svm_bo of prange got released in a while loop should reschedule current task to give other tasks oppotunity to run, specially the the workque task that handles svm_bo ref release, otherwise we may enter to softlock. Signed-off-by: Xiaogang.Chen Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 22a70aaccf13c..86135ca33e5be 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -433,11 +433,11 @@ svm_range_validate_svm_bo(struct amdgpu_device *adev, struct svm_range *prange) /* We need a new svm_bo. Spin-loop to wait for concurrent * svm_range_bo_release to finish removing this range from - * its range list. After this, it is safe to reuse the - * svm_bo pointer and svm_bo_list head. + * its range list and set prange->svm_bo to null. After this, + * it is safe to reuse the svm_bo pointer and svm_bo_list head. */ - while (!list_empty_careful(&prange->svm_bo_list)) - ; + while (!list_empty_careful(&prange->svm_bo_list) || prange->svm_bo) + cond_resched(); return false; } -- 2.42.0