From: Phillip Susi <psusi@cfl.rr.com>
To: Dong Feng <middle.fengdong@gmail.com>
Cc: pradeep singh <2500.pradeep@gmail.com>,
Bahadir Balban <bahadir.balban@gmail.com>,
Learning Linux <learninglinux4@gmail.com>,
kernelnewbies@nl.linux.org, linux-newbie@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: Why can't we sleep in an ISR?
Date: Tue, 15 May 2007 12:57:36 -0400 [thread overview]
Message-ID: <4649E680.9020102@cfl.rr.com> (raw)
In-Reply-To: <a2ebde260705142345m440c70fbu33934334fbb69f8e@mail.gmail.com>
Dong Feng wrote:
>> Doesn't it run in current process's context ?
>>
>
> No. I think the concept of process context is a higher-level logical
> concept. Though the interrupt share stack with the interrupted
> process, in my opinion it logically does not share the context with
> the process.
No, the term context here has a specific meaning. It refers to those
things which flow from the current pointer, including the virtual memory
space, file descriptor table, current uid, and so forth. Because the
current pointer is not changed on entry to an ISR, the ISR is executing
in the context of the interrupted process, and thus uses that process'
virtual memory, etc.
next prev parent reply other threads:[~2007-05-15 16:57 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-14 6:37 Why can't we sleep in an ISR? Learning Linux
[not found] ` <366312910705140010m78b215a2t1753445e81120288@mail.gmail.com>
2007-05-14 7:16 ` Learning Linux
2007-05-14 15:24 ` Bahadir Balban
2007-05-14 15:56 ` Dong Feng
[not found] ` <366312910705142217geba69dbm98a6c0bf2aabb937@mail.gmail.com>
2007-05-15 6:45 ` Dong Feng
[not found] ` <366312910705150010p623f9732mc498f457245d23a1@mail.gmail.com>
2007-05-15 7:28 ` Dong Feng
2007-05-15 8:40 ` Learning Linux
2007-05-15 8:58 ` Dong Feng
2007-05-15 16:57 ` Phillip Susi [this message]
2007-05-15 17:23 ` David Schwartz
2007-05-15 22:49 ` Dong Feng
2007-05-16 15:20 ` Phillip Susi
2007-05-16 23:17 ` Dong Feng
2007-05-17 16:07 ` Phillip Susi
2007-05-17 23:50 ` Dong Feng
2007-05-14 12:25 ` Helge Hafting
[not found] ` <366312910705140552o6a507cbbl806f2ad0efc9d90c@mail.gmail.com>
2007-05-14 13:36 ` Dong Feng
-- strict thread matches above, loose matches on Subject: below --
2007-05-14 15:22 linux
2007-05-14 15:55 ` Rik van Riel
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