Date: Mon, 26 Aug 2002 13:29:56 -0400 (EDT) From: John Baldwin <jhb@FreeBSD.org> To: Maksim Yevmenkin <myevmenk@exodus.net> Cc: hackers@FreeBSD.ORG, "M. Warner Losh" <imp@bsdimp.com> Subject: Re: Fast interrupts Message-ID: <XFMail.20020826132956.jhb@FreeBSD.org> In-Reply-To: <3D6A5A47.57672729@exodus.net>
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On 26-Aug-2002 Maksim Yevmenkin wrote: > John Baldwin wrote: >> >> On 26-Aug-2002 M. Warner Losh wrote: >> > can you call wakeup(9) from a fast interrupt handler? > > [ ...] > >> > The only reason I ask is because sio seems to go out of its way to >> > schedule a soft interrupt to deal with waking up processes, which then >> > calls wakeup... >> >> Since wakeup only needs a spin lock, it is probably ok. You just can't call >> anything that would sleep (in any interrupt handler) or block on a non-spin >> mutex. > > what is the general locking technique for interrupt handlers? > there must be some sort of locking, right? Normal interrupt handlers should use MTX_DEF mutexes. Fast interrupt handlers cannot use those, so they must use MTX_SPIN mutexes instead. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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