Re: Best method for sending messages to user space?

From: Dan Williams
Date: Tue Oct 21 2008 - 16:42:56 EST

On Tue, Oct 21, 2008 at 1:23 PM, Timur Tabi <timur@xxxxxxxxxxxxx> wrote:
> Dan Williams wrote:
>> fd = open("/sys/block/md0/md/array_state");
>> do {
>> read(buf, fd, len);
>> act_on_message(buf);
>> select(...); /* wait for next sysfs_notify event */
>> lseek(fd, 0, SEEK_SET); /* seek back so we can read the new state */
>> } while (1);
> I meant from the kernel side. I added a call to sysfs_notify(), and I didn't
> see any sysfs entries being created, so I presume I need to set up sysfs before
> I call sysfs_notify(), but I can't figure out what that setup is.

sysfs_notify() will not create any files it only operates on
pre-existing attributes created via kobject_{init_and_}add(). See:
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