Date: Sun, 03 May 1998 18:59:26 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Matthew Dillon <dillon@backplane.com> Cc: Nate Williams <nate@mt.sri.com>, freebsd-bugs@FreeBSD.ORG Subject: Re: i386/5398 Message-ID: <11689.894214766@critter.freebsd.dk> In-Reply-To: Your message of "Sun, 03 May 1998 09:33:47 PDT." <199805031633.JAA04427@apollo.backplane.com>
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In message <199805031633.JAA04427@apollo.backplane.com>, Matthew Dillon writes: > How is XFree86, a userland program, able to disable interrupts ? > The Hardware blitter/PCI latency also seems impossible, 115200 = > 11.5 KBytes/sec = 86uS per character x the FIFO depth (after the hack) > of 4 or 8 character times is over 500uS. It just doesn't make any > sense. By monopolizing the PCI bus, while blitting 3 or 4 MB data, I can certainly see PCI starvation. Remeber that to blt 3 MB around, you have to read 3 MB and write 3MB, so that is 6MB over a 133MB/sec bus, giving a minimum duration of 45 msec per blt. Why do you think BLT is being put into the graphics chip by so many people ? Now, can we stop this futile waste of everybodys time ? Thankyou! -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." "ttyv0" -- What UNIX calls a $20K state-of-the-art, 3D, hi-res color terminal To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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