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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 ABE9AC2D0DB for ; Fri, 31 Jan 2020 18:07:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8386820CC7 for ; Fri, 31 Jan 2020 18:07:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580494035; bh=RgD0a05yAr5oVXyE0rsfH+k3SKcawpwF5zZfalvHDN8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=GcDEOEpBVCkUu7peK0Tlp2m2MJAi0LO3k/FvRWOCXRjiPJ9p6j46/MXH7kwKa+1/3 0RKcRBnOCU8lUHFf3jQQHHmLnl1Ynuix6rRFjx0P7wSO3/azca6AIsEzoWdSnrzYac MVQl7sDk+MrOH5F/rYCi+XBX1bZxcGJ3yUADxAeM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727250AbgAaSHO (ORCPT ); Fri, 31 Jan 2020 13:07:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:59432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726712AbgAaSHO (ORCPT ); Fri, 31 Jan 2020 13:07:14 -0500 Received: from cakuba.hsd1.ca.comcast.net (unknown [199.201.64.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 472AA20663; Fri, 31 Jan 2020 18:07:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580494033; bh=RgD0a05yAr5oVXyE0rsfH+k3SKcawpwF5zZfalvHDN8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=gwLauG9XNDz2ScE7FSn24p0X+tmhu2GZBcbzOk6zn/9riChg3Hf3p96UKnFWUhU1h dh9try5fDlpO7cYELGYbJSAmL9P59skZXC9rk2v7r/l2EEbd06xTO6ZVIAz/zpwwRS kLxNo+BnUzzmwQjtLfQL6wzlCMVInp+rLJrnsvQU= Date: Fri, 31 Jan 2020 10:07:12 -0800 From: Jakub Kicinski To: Jacob Keller Cc: netdev@vger.kernel.org, jiri@resnulli.us, valex@mellanox.com, linyunsheng@huawei.com, lihong.yang@intel.com Subject: Re: [PATCH 04/15] netdevsim: support taking immediate snapshot via devlink Message-ID: <20200131100712.5ba1ce65@cakuba.hsd1.ca.comcast.net> In-Reply-To: <20200130225913.1671982-5-jacob.e.keller@intel.com> References: <20200130225913.1671982-1-jacob.e.keller@intel.com> <20200130225913.1671982-5-jacob.e.keller@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 30 Jan 2020 14:58:59 -0800, Jacob Keller wrote: > Implement the .snapshot region operation for the dummy data region. This > enables a region snapshot to be taken upon request via the new > DEVLINK_CMD_REGION_SNAPSHOT command. > > Signed-off-by: Jacob Keller > --- > drivers/net/netdevsim/dev.c | 38 +++++++++++++++---- > .../drivers/net/netdevsim/devlink.sh | 5 +++ > 2 files changed, 36 insertions(+), 7 deletions(-) > > diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c > index d521b7bfe007..924cd328037f 100644 > --- a/drivers/net/netdevsim/dev.c > +++ b/drivers/net/netdevsim/dev.c > @@ -38,24 +38,47 @@ static struct dentry *nsim_dev_ddir; > > #define NSIM_DEV_DUMMY_REGION_SIZE (1024 * 32) > > +static int nsim_dev_take_snapshot(struct devlink *devlink, nit: break the line after static int, you've done it in other patches so I trust you agree it's a superior formatting style :) > + struct netlink_ext_ack *extack, > + u8 **data, > + devlink_snapshot_data_dest_t **destructor) > +{ > + void *dummy_data; > + > + dummy_data = kmalloc(NSIM_DEV_DUMMY_REGION_SIZE, GFP_KERNEL); > + if (!dummy_data) { > + NL_SET_ERR_MSG(extack, "Out of memory"); Unnecessary, there will be an OOM splat, and ENOMEM is basically exactly the same as the message. > + return -ENOMEM; > + } > + > + get_random_bytes(dummy_data, NSIM_DEV_DUMMY_REGION_SIZE); > + > + *data = dummy_data; > + *destructor = kfree; Is there any driver which uses different destructor for different snapshots? Looks like something we could put in ops, maybe? > + return 0; > +} > + > static ssize_t nsim_dev_take_snapshot_write(struct file *file, > const char __user *data, > size_t count, loff_t *ppos) > { > struct nsim_dev *nsim_dev = file->private_data; > - void *dummy_data; > + devlink_snapshot_data_dest_t *destructor; > + u8 *dummy_data; > int err; > u32 id; > > - dummy_data = kmalloc(NSIM_DEV_DUMMY_REGION_SIZE, GFP_KERNEL); > - if (!dummy_data) > - return -ENOMEM; > - > - get_random_bytes(dummy_data, NSIM_DEV_DUMMY_REGION_SIZE); > + err = nsim_dev_take_snapshot(priv_to_devlink(nsim_dev), NULL, > + &dummy_data, &destructor); > + if (err) { > + pr_err("Failed to capture region snapshot\n"); Also not a very useful message for netdevsim IMHO give the caller clearly requested a snapshot and will get a more informative error from errno. > + return err; > + } > > id = devlink_region_snapshot_id_get(priv_to_devlink(nsim_dev)); > err = devlink_region_snapshot_create(nsim_dev->dummy_region, > - dummy_data, id, kfree); > + dummy_data, id, destructor); > if (err) { > pr_err("Failed to create region snapshot\n"); > kfree(dummy_data);