Date: Wed, 30 Jun 1999 23:55:29 -0700 From: "Ulairi" <ulairi@jps.net> To: <lnb@cybertouch.org> Cc: "Newbies" <freebsd-newbies@freebsd.org> Subject: RE: reentrant kernel Message-ID: <000901bec38e$b4d84fc0$29c4edd0@ulairi> In-Reply-To: <199907010116.VAA94928@freedom.cybertouch.org>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 A re-entrant kernel is a kernel whose functions are designed to run on multiple CPUs at once. Simplified, here's the thing: when kernel's threads make system calls (request resources, whatever), they will block other threads from getting the same resources until the first thread has finished. With multiple CPUs, that's really SILLY since you should be able to say "thread A doing memory allocation goes onto CPU1, thread B doing memory allocation goes onto CPU2". At this time, of Linux/FreeBSD/WindowsNT, only NT's kernel is actually re-entrant. Linux's and FreeBSD's are both at various stages of development. Windows NT 4.0's Service Pack 4 adds a very important fix - - it makes the network card driver reentrant so that an SMP (Symmetrical Multiple Processors)-based system can have more then one CPU talk to the network driver and process network information at the same time. A thread is a mini-process - a part of a kernel designed to do something. They exist so that they can be deligated tasks and the main thing keeps on chugging along | | Hello, | Just a quick question. What is a reentrant kernel? | | Thanks, | | Lanny -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.0.2i iQA/AwUBN3sPIFR8Yh25VFLEEQKK0wCgivyCV9YCvBd887WWNc7/dF3NfloAn3fm kpotyFaT9baAK5FeL//NeCVW =ErFW -----END PGP SIGNATURE----- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-newbies" in the body of the message
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