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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 B7C83C2D0DB for ; Fri, 31 Jan 2020 18:13:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9815620CC7 for ; Fri, 31 Jan 2020 18:13:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725939AbgAaSNV (ORCPT ); Fri, 31 Jan 2020 13:13:21 -0500 Received: from mga07.intel.com ([134.134.136.100]:65470 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725268AbgAaSNV (ORCPT ); Fri, 31 Jan 2020 13:13:21 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jan 2020 10:12:20 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,386,1574150400"; d="scan'208";a="377415638" Received: from jekeller-mobl1.amr.corp.intel.com (HELO [134.134.177.86]) ([134.134.177.86]) by orsmga004.jf.intel.com with ESMTP; 31 Jan 2020 10:12:19 -0800 Subject: Re: [PATCH 04/15] netdevsim: support taking immediate snapshot via devlink To: Jakub Kicinski Cc: netdev@vger.kernel.org, jiri@resnulli.us, valex@mellanox.com, linyunsheng@huawei.com, lihong.yang@intel.com References: <20200130225913.1671982-1-jacob.e.keller@intel.com> <20200130225913.1671982-5-jacob.e.keller@intel.com> <20200131100712.5ba1ce65@cakuba.hsd1.ca.comcast.net> From: Jacob Keller Organization: Intel Corporation Message-ID: Date: Fri, 31 Jan 2020 10:12:19 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <20200131100712.5ba1ce65@cakuba.hsd1.ca.comcast.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 1/31/2020 10:07 AM, Jakub Kicinski wrote: > 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 :) > Sure. >> + 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? > Hmm. Yea I think you're right making this tied to the ops structure instead of the callback makes sense to me. >> + 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. > Will remove. >> + 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);