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From: Ken Brown <kbrown@cornell.edu>
To: "Lavrentiev, Anton (NIH/NLM/NCBI) [C]" <lavr@ncbi.nlm.nih.gov>
Cc: "'cygwin@cygwin.com'" <cygwin@cygwin.com>
Subject: Re: mmap failure [was: cygrunsrv + sshd + rsync = 20 times too slow -- throttled?]
Date: Tue, 7 Sep 2021 18:44:54 -0400	[thread overview]
Message-ID: <07cb816c-0bca-440d-338d-fefb110d4a41@cornell.edu> (raw)
In-Reply-To: <SJ0PR09MB7102405FB7D88E4AF44E9498A5D39@SJ0PR09MB7102.namprd09.prod.outlook.com>

On 9/7/2021 5:52 PM, Lavrentiev, Anton (NIH/NLM/NCBI) [C] wrote:
>>>
>>> With undocumented structure member initialization an issue, maybe better to
>>> future proof using e.g.
>>>
>>>       MEM_EXTENDED_PARAMETER mmap_ext = { 0 }; // or memset or bzero
>>
>> I don't see what this would accomplish.  We're already initializing every member
>> after Corinna's last patch.
>>
> 
> Well, if one day MS decides to use some of the Reserved field by splinting off a new
> named field out of that bulk of bits, the code will be in trouble again...
> While with memset, bzero or C-style initializer, everything is guaranteed to be zapped with 0.

MS can't add a new named field to a documented struct without breaking a lot of 
code.  I think it's extremely unlikely that they would do that.  On the other 
hand, I think it's very likely that a reader of the Cygwin code would be 
confused by code that initializes a struct to 0 prior to assigning a value to 
every member.

Ken

  reply	other threads:[~2021-09-07 22:44 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-24 19:49 cygrunsrv + sshd + rsync = 20 times too slow -- throttled? Chris Roehrig
2021-08-24 23:43 ` Mark Geisert
2021-08-25  0:35   ` Chris Roehrig
2021-08-25  2:12     ` Chris Roehrig
2021-08-25  2:02 ` NightStrike
2021-08-25  3:20   ` Mark Geisert
2021-08-25 17:24     ` Chris Roehrig
2021-08-25 11:18 ` Takashi Yano
2021-08-25 17:31   ` Chris Roehrig
2021-08-25 17:52   ` Ken Brown
2021-08-25 18:18     ` Chris Roehrig
2021-08-25 18:51       ` Chris Roehrig
2021-08-26 15:44       ` Ken Brown
2021-08-25 20:33     ` Mario Emmenlauer
2021-08-26 15:47       ` Ken Brown
2021-08-25 21:29     ` Takashi Yano
2021-08-26 15:56       ` Ken Brown
2021-08-26 22:18         ` Ken Brown
2021-08-27 11:24           ` Takashi Yano
2021-08-27 16:00             ` Ken Brown
2021-08-27 17:21               ` Takashi Yano
2021-08-28  2:00                 ` Takashi Yano
2021-08-28  3:03                   ` Takashi Yano
2021-08-28  8:43                 ` Corinna Vinschen
2021-08-28  9:41                   ` Takashi Yano
2021-08-28 11:58                     ` Corinna Vinschen
2021-08-28 15:43                       ` Takashi Yano
2021-08-28 20:55                         ` Ken Brown
2021-08-29  8:41                           ` Takashi Yano
2021-08-29 22:42                             ` Ken Brown
2021-08-29 10:27                         ` Corinna Vinschen
2021-08-29  9:07                     ` Takashi Yano
2021-08-29 15:57                       ` Ken Brown
2021-08-29 19:24                         ` Chris Roehrig
2021-08-29 22:24                           ` Ken Brown
2021-08-30 23:58                             ` Chris Roehrig
2021-08-31 19:05                               ` Ken Brown
2021-08-31 19:53                                 ` Chris Roehrig
2021-08-31 20:23                                   ` Chris Roehrig
2021-08-31 21:29                                     ` Brian Inglis
2021-09-01 21:11                                     ` Chris Roehrig
2021-09-02 15:25                                       ` Ken Brown
2021-09-02 19:03                                         ` Chris Roehrig
2021-09-03 17:26                                           ` Ken Brown
2021-09-03 19:55                                           ` Corinna Vinschen
2021-09-03 20:59                                             ` Chris Roehrig
2021-09-04  8:32                                               ` Achim Gratz
2021-09-04 16:45                                               ` Brian Inglis
2021-09-05  8:18                                                 ` Achim Gratz
2021-09-05 15:11                                                   ` Brian Inglis
2021-09-06 10:42                                                     ` Achim Gratz
2021-09-04 22:37                                             ` mmap failure [was: cygrunsrv + sshd + rsync = 20 times too slow -- throttled?] Ken Brown
2021-09-04 22:54                                               ` Ken Brown
2021-09-04 22:58                                                 ` Ken Brown
2021-09-05  0:04                                                   ` Ken Brown
2021-09-05 13:24                                                     ` Ken Brown
2021-09-06 15:32                                                       ` Corinna Vinschen
2021-09-06 17:12                                                         ` Ken Brown
2021-09-06 17:38                                                           ` Ken Brown
2021-09-06 17:43                                                             ` Eliot Moss
2021-09-06 17:59                                                             ` Corinna Vinschen
2021-09-06 18:07                                                               ` Corinna Vinschen
2021-09-06 18:40                                                                 ` Ken Brown
2021-09-06 20:52                                                                   ` Peter Dons Tychsen
2021-09-06 20:54                                                                   ` Peter Dons Tychsen
2021-09-06 21:24                                                                     ` Ken Brown
2021-09-06 21:31                                                                       ` Ken Brown
2021-09-07  3:34                                                                       ` Brian Inglis
2021-09-07 16:28                                                                         ` Ken Brown
2021-09-07 21:52                                                                           ` Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2021-09-07 22:44                                                                             ` Ken Brown [this message]
2021-09-08  6:14                                                                               ` Sam Edge
2021-09-08  8:18                                                                         ` Corinna Vinschen
2021-09-07 21:41                                                                       ` Peter Dons Tychsen
2021-09-04 23:18                                               ` Brian Inglis
2021-08-29 19:37                         ` cygrunsrv + sshd + rsync = 20 times too slow -- throttled? Takashi Yano
2021-08-29 21:09                           ` Ken Brown
2021-08-29 21:04                       ` Ken Brown
2021-08-30  0:13                         ` Takashi Yano
2021-08-30  0:22                           ` Takashi Yano
2021-08-30  2:15                             ` Ken Brown
2021-08-30  8:02                               ` Takashi Yano
2021-08-28 15:17                   ` Ken Brown
2021-09-16 22:00 ` Keith Christian
2021-09-16 22:48   ` Ken Brown
2021-09-16 22:58     ` Keith Christian

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