Re: [PATCH] Make remote transfers interruptible

[Doug Evans <dje@google.com>]

On Wed, Aug 12, 2015 at 10:31 AM, Sandra Loosemore
<sandra@codesourcery.com> wrote:
> On 08/12/2015 08:30 AM, Gary Benson wrote:
>>
>> Hi Sandra,
>>
>> Sandra Loosemore wrote:
>>>
>>> On 08/05/2015 09:28 AM, Gary Benson wrote:
>>>>
>>>> This commit makes it possible to interrupt slow remote file transfers.
>>>>
>>>> gdb/ChangeLog:
>>>>
>>>>         * gdb_bfd.c (gdb_bfd_iovec_fileio_pread): Add QUIT call.
>>>
>>>
>>> It still does not work for me.  :-(
>>
>>
>> Could you please try this newer version and see if it allows you to
>> interrupt the remote transfers?
>
>
> This version still doesn't make the transfer interruptable with ^C. *But*,
> with this patch, the startup time is reduced from 4 minutes to 19 seconds.
> Huh?  Is it really transferring the entire file contents, or was the time
> being used for some GDB-side operation that is quadratic or exponential in
> the size of the read requested rather than the actual byte transfer?
> Independently of the ^C issue, I think we need to better understand what is
> going on here and better tune the code on both sides of the RSP for large
> file transfers.  Even if a user asks for target-side libraries explicitly, 4
> minutes to transfer one library doesn't provide a good user experience, and
> 19 seconds isn't so great either when you consider that some interactive
> applications link with dozens of GUI or multimedia libraries and not just
> glibc.

Dozens?  How about thousands.  1/2 :-)

[just want to make sure such cases are in the mindset of the community]