lkml.org 
[lkml]   [2008]   [Jun]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Ctrl+C doesn't interrupt process waiting for I/O
Jeremy Fitzhardinge wrote:
> Török Edwin wrote:
>> Hi,
>>
>> I have encountered the following situation several times, but I've been
>> unable to come up with a way to reproduce this until now:
>> - some process is keeping the disk busy (some cron job for example:
>> updatedb, chkrootkit, ...)
>> - other processes that want to do I/O have to wait (this is normal)
>> - I have a (I/O bound) process running in my terminal, and I want to
>> interrupt it with Ctrl+C
>> - I type Ctrl+C several times, and the process is not interrupted for
>> several seconds (10-30 secs)
>> - if I type Ctrl+Z, and use kill %1 the process dies faster than
>> waiting for it to react to Ctrl+C
>>
>> This issue occurs both on my x86-64 machine that uses reiserfs, and on
>> my x86 machine that uses XFS, so it doesn't seem related to the
>> underlying FS.
>> I use 2.6.25-2 and 2.6.26-rc8 now; I don't recall seeing this behaviour
>> with old kernels (IIRC I see this since 2.6.21 or 2.6.23).
>>
>> Is this intended behaviour, or should I report a bug?
>>
>
> Yes, it's intended behaviour. Filesystem IO syscalls are considered
> "fast" and are interruptible. Usermode code can reasonably expect
> that file IO will never return EINTR.

That's filesystem dependent; if you mount an nfs filesystem with the
'intr' mount option, it will be interruptible (which makes sense, as it
is impossible to guarantee the server's responsiveness).

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2008-06-29 05:45    [W:0.173 / U:1.756 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site