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mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.onmicrosoft.com; s=selector2-citrix-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=0ofQkRP8G45OxjduCSyQew8JrLk/98Ast4e8Diq4WgE=; b=NsgQnnbnw0NoK0hUM9sqCFy0Aep3SzhIPZpMijJI/qPgJwuqKHvocoGHoYWZfmOEDVxjG8wFPgqs9Ct0INO0y1XADEmre2Bc/KmkhT8SGJOxk+WbExx1y2WWkg2w2TqpxkgMK9sWoFEFLloKbqqOHe8SUyofvCVlI8shiU08esk= Subject: Re: [PATCH v7 08/10] tools/misc: Add xen-vmtrace tool To: Ian Jackson CC: Xen-devel , =?UTF-8?Q?Micha=c5=82_Leszczy=c5=84ski?= , Wei Liu , Tamas K Lengyel References: <20210121212718.2441-1-andrew.cooper3@citrix.com> <20210121212718.2441-9-andrew.cooper3@citrix.com> <24586.61484.451595.44272@mariner.uk.xensource.com> <24592.1081.38318.522643@mariner.uk.xensource.com> From: Andrew Cooper Message-ID: <445bd883-3900-6a28-10e9-84251af43123@citrix.com> Date: Tue, 26 Jan 2021 12:55:09 +0000 User-Agent: Mozilla/5.0 (X11; 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X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?R2JUSGhIM2RPWS9NcXJwQ0w2U092VkdzV3VXcmZRdU5aYmpyd2VVMkp5azVX?= =?utf-8?B?T1VsQklIVHA1Y0NncTdJRXhWTEpRdEVrTHoxY0hzekVkY1pmaTlwYWl4aGg5?= =?utf-8?B?VWVzVFUyM256cFdDam9rdGRqSGo1YjBGY2FFS3k3N291RTRyOHliK1JqZXBI?= =?utf-8?B?MkZ5SGFBMG1LcXo2ZnVzR3dwVlZVZlBCTjhOV0ZFU2ZyanBGWkpsSU1TdWRF?= =?utf-8?B?QmdlaHFvMEdjK01IcnExcHpEdzE2bHg5VjBpMFFLdVVaRE9PZldHRy92bnRI?= =?utf-8?B?QVYzZ01mNHNmTjV1MnNRZkY3WE0vaGw2WGQrOTFhV2RRZGFaZDViVjNSeHpZ?= =?utf-8?B?QlhTa2t1SXdOZmZKU3Zybys0MTVwRVNKT0d6Wmd4SEhlNTZGQ09OYk1jVkpR?= =?utf-8?B?ZVR5SlB6cER0WjFJKytQcTlETzZXcWRuZUZqZ2NtMW02cWZ1VWdGbmhWNko0?= =?utf-8?B?cnlMajZIQ1ZhZmdsL1ZRMCsyN3lDZ2d2bk1vT1BxK0M2VnZNYzE1SDY2Y0du?= =?utf-8?B?Yi9tcXdhbThtTlczWkhzWStNa1FCSjdadnZSY0hGako0WDBWWGwybldYSnU0?= =?utf-8?B?OVN1d0dhYlpMamlzQy82THcrd2JyZTllc2pRcy9OSjA3TkpCUkt4OFBhc21B?= =?utf-8?B?ZDRPQUtxZ2N3b1BkaHhYZUhia050TWlhRE9Ob2o3T3ZpVFlJSnFzdlNZSi9E?= =?utf-8?B?TUZSVHFBNHRUK0ZnUTdlR1lDcU5Ud2I3MG9hS3BaRjhIaEp2Q05qY014UEgw?= =?utf-8?B?SUp1Q1d6ZFNRMUF1b3FvOWNhVmIydnFCT3E3RmY4ZjRmaGhodnFUbUhXdVFJ?= =?utf-8?B?WkJTWFF0cmxPU2ZjWElpSFZsaUdYTis4bndoVForSDVQNjlCak8yRm1reTFH?= =?utf-8?B?NnhtYis1NTdEd2JObUgzaUJacUlQY1NXa1g3aEYycGVMaXVtM2JDckRTekRn?= =?utf-8?B?VzZiSjlodHhKNGNOZVVFRnZneTk2S2F1QlRUem5kMkNOMzZ0bzlXZzU3RjF6?= =?utf-8?B?ZHFwYWovTXJldzg0YUNxNm5JRkh5czF4ZVlKbFd5TDJOV3JQZjAxaXR4Tjht?= =?utf-8?B?U1h4bEJQbllqa1J4T3Zoank3cHhoUi9acWFzSHdRZUdlVlFidkErVkliNk5I?= =?utf-8?B?c0pFNlV5eG4xOEtzQVQxZGxHdWZxQllBQUxRU3NPNEYwQjJFQzhWZ3BKTHVy?= =?utf-8?B?cDk0c0pNSXc3aGZGZEVFTmo1SlZsNFJ6M2JZWmpvc3lHSnBWdDBwaWRjbDhK?= =?utf-8?B?UEplWjJKRXkvTWtSNmFBR0UrOHpqVnF4eFF1dUFoU01KaTkvZ0RSR2FGR0Mw?= =?utf-8?B?Q0x1aGU0Sno0RUZFVmtsY2Qxakp5VFRLbHd0MW5wWVN0SkZOU1A2c3prV09y?= =?utf-8?B?R0d6aVNVaTkyZEp0b2NKRVlLTWNTNjRtRW1RVkNxUkhZQ01XNEw4dHVyTVhv?= =?utf-8?Q?/AWxsIOA?= X-MS-Exchange-CrossTenant-Network-Message-Id: 085a2bfd-2fb4-41b9-1b5b-08d8c1f9a09c X-MS-Exchange-CrossTenant-AuthSource: BYAPR03MB4728.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jan 2021 12:55:15.9767 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 335836de-42ef-43a2-b145-348c2ee9ca5b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: gMx/PoY/L3fvf0/SdM4HD+i/0KLt1jhvaKUTJ3E7QIQ63OEDc99QfnvBzENfSIErzHmRBZX8dfdpwTRDBsxd3Gn/A3CBLAV8iVHnOSpmCNM= X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR03MB3416 X-OriginatorOrg: citrix.com On 26/01/2021 11:59, Ian Jackson wrote: >>> Also: at the very least, you need to trap SIGTERM SIGHUP SIGPIPE. >>> >>> It would be good to exit with the right signal by re-raising it. >> This is example code, not a production utility. > Perhaps the utility could print some kind of health warning about it > possibly leaving this perf-impacting feature enabled, and how to clean > up ? Why?  The theoretical fallout here is not conceptually different to libxl or qemu segfaulting, or any of the myriad other random utilities we have. Printing "Warning - this program, just like everything else in the Xen tree, might in exceptional circumstances segfault and leave the domain in a weird state" is obvious, and doesn't need stating. The domain is stuffed. `xl destroy` may or may not make the problem go away. ~Andrew