From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <397DDB36.DA5B68F9@mvista.com> Date: Tue, 25 Jul 2000 11:23:50 -0700 From: Jun Sun MIME-Version: 1.0 To: Geert Uytterhoeven CC: Iain Sandoe , linuxppc-dev@lists.linuxppc.org Subject: Re: [ANN] IRQ Latency tool 0.1.3 release. References: Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Geert Uytterhoeven wrote: > > On Mon, 24 Jul 2000, Iain Sandoe wrote: > > BTW: on my system ll_rw_blk.c gets up to 750 us quite often when the system > > is loaded... this **IS** a potential problem for audio use. > > > > log entry : 3 (16 history entries) > > Peak Block Time : 430.0 us ( 7185) [ OK ] > > startFilename : ll_rw_blk.c Line : 167 > > endFileName : ll_rw_blk.c Line : 179 > > > > I still haven't found the "hard-block" that is effecting the overall audio > > latency performance... ah well, back to the drawing board... > > Do you have IDE? The IDE driver turned out to be the major interrupt messing > problem on m68k, since it can disable interrupts for quite a while. > > Gr{oetje,eeting}s, > > Geert The IDE driver in v2.2.xx has a run-away cli(), which causes long interrupt blocking times. See my postings in linux-kernel mailing list a while back (around March), if you can still find them. A IDE driver guys suggested a fix, but I am not sure if it there yet. The function is do_rw_dis(). log entry : 3 (unplug_device in ll_rw_blk.c, calling dev->request_fn(), do_rw_disk() in ide-disk.c) blockingTime : 39955 startFileName : ide-disk.c startFileLine : 390 startCount : 3433912489 endFileName : ll_rw_blk.c endFileLine : 172 endCount : 3433952444 unused1,2 : 0, 0 I believe there is a user-land workaround, which involves using "hdparm" to change some bits. Jun ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/