From: Dinesh Nair <[EMAIL PROTECTED]> Subject: Re: locking in a device driver Date: Thu, 03 Nov 2005 02:23:32 +0800
> > > On 10/28/05 10:52 M. Warner Losh said the following: > > libc_r will block all other threads in the application while an ioctl > > executes. libpthread and libthr won't. I've had several bugs at work > > so if the userland thread does an ioctl, and the the driver goes to > tsleep() when the ioctl is received, all other threads are also blocked > from executing, i.e wont be context switched to run ? Yes. if you tsleep with signals enabled, the periodic timer will go off, and you'll return early. This typically isn't what you want either. > is this behaviour only 4.x specific or is it also there in 5.x ? This behavior is libc_r specific. Any userland threadding library will have these issues. It is fundamental to how userland threadding works. If you use libc_r on 5, you'll see exactly this behavior. If you use libpthread or libthr, you won't. Warner _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"