Re: MDELAY()
Hi, DELAY() in FreeBSD uses a busy loop . I am looking for something like sleep_on_timeout() call in Linux . (dont' want to waste the CPU cycles by DELAY'ing) As I am pretty new to programming with Free BSD , can you help me with some details about equivalent implementation(wait queues etc) in Free BSD . ---Dip On 4/13/05, Brooks Davis [EMAIL PROTECTED] wrote: On Wed, Apr 13, 2005 at 02:33:22AM +0530, Dipjyoti Saikia wrote: Hi, Can any one help me out with a better Implementation of MDELAY() in FreeBSD kernel 4.10 Please start by defining better. -- Brooks -- Any statement of the form X is the one, true Y is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: MDELAY()
On Fri, 15 Apr 2005 21:46, Dipjyoti Saikia wrote: DELAY() in FreeBSD uses a busy loop . I am looking for something like sleep_on_timeout() call in Linux . (dont' want to waste the CPU cycles by DELAY'ing) tsleep/msleep/timeout are probably what you want. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au The nice thing about standards is that there are so many of them to choose from. -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpZBDhyMCe8D.pgp Description: PGP signature
Re: MDELAY()
[EMAIL PROTECTED] wrote: DELAY() in FreeBSD uses a busy loop . I am looking for something like sleep_on_timeout() call in Linux . (dont' want to waste the CPU cycles by DELAY'ing) You may want to check out timeout(9) / untimeout(9), see man 9 timeout for details. As I am pretty new to programming with Free BSD , can you help me with some details about equivalent implementation(wait queues etc) in Free BSD . Reading the man pages for asleep(9) / wakeup(9) should give you a good introduction. ALeine ___ WebMail FREE http://mail.austrosearch.net ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: MDELAY()
sleep_on_timeout() call in Linux . (dont' want to waste the CPU cycles You may want to try the manual pages. % man -k sleep | fgrep '(9)' endtsleep(9), sleepinit(9), unsleep(9) - manage the queues of sleeping processes init_sleepqueues(9) ... sleepq_wait_sig(9) - manage the queues of sleeping threads sleep(9), msleep(9), tsleep(9), wakeup(9) - wait for events vm_page_sleep_busy(9)- wait for a busy page to become unbusy % man -k DELAY | fgrep '(9)' DELAY(9) - busy loop for an interval -- FreeBSD Volunteer, http://people.freebsd.org/~jkoshy ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: MDELAY()
On Fri, Apr 15, 2005 at 06:03:11AM -0700, ALeine wrote: [EMAIL PROTECTED] wrote: DELAY() in FreeBSD uses a busy loop . I am looking for something like sleep_on_timeout() call in Linux . (dont' want to waste the CPU cycles by DELAY'ing) You may want to check out timeout(9) / untimeout(9), see man 9 timeout for details. You should not use timeout(9) without a very good reason, the callout_* interface is prefered. Joerg ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: MDELAY()
On Sat, 16 Apr 2005 00:34, Joerg Sonnenberger wrote: You may want to check out timeout(9) / untimeout(9), see man 9 timeout for details. You should not use timeout(9) without a very good reason, the callout_* interface is prefered. Can someone add a warning to the top of the makefile similar to the one for spl? -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au The nice thing about standards is that there are so many of them to choose from. -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C pgpGG3Fv9PUgX.pgp Description: PGP signature
Re: MDELAY()
On Sat, Apr 16, 2005 at 01:12:42AM +0930, Daniel O'Connor wrote: On Sat, 16 Apr 2005 00:34, Joerg Sonnenberger wrote: You may want to check out timeout(9) / untimeout(9), see man 9 timeout for details. You should not use timeout(9) without a very good reason, the callout_* interface is prefered. Can someone add a warning to the top of the makefile similar to the one for spl? It's not that bad, timeout(9) has a few cases, where replacing it involves work. I've done that in DragonFly, I know what I'm talking about. The reason for this advice is that the timeout(9) API has two major short comings: (a) It depends on some internal magic to provide the storage, but doesn't have a clear way to handle errors. The storage space can be a few hundred KB of kernel memory mostly wasted. (b) It is difficult to cancel all outstanding timers correctly because the race conditions are difficult to avoid when calling untimeout. Since (b) is pretty much a requirement for the kernel nowaday and you have to keep track of the return value anyway, you can almost mechanically convert such code to the callout_* interface. That also avoids (a). Concerning your original question about the inefficiency of DELAY, what timeouts are we talking about? For anything in the area of a few micro seconds, DELAY is most likely better, because it avoids context switches and the associated cache pollution. Joerg ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: MDELAY()
On Wed, Apr 13, 2005 at 02:33:22AM +0530, Dipjyoti Saikia wrote: Hi, Can any one help me out with a better Implementation of MDELAY() in FreeBSD kernel 4.10 Please start by defining better. -- Brooks -- Any statement of the form X is the one, true Y is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 pgpyw5cCscSTf.pgp Description: PGP signature
