* Re: [Xenomai-core] [Xenomai-commits] r4392 - /trunk/include/asm-x86/arith_64.h [not found] <E1L1XPO-0006Xh-1s@domain.hid> @ 2008-11-16 10:35 ` Jan Kiszka 2008-11-16 12:13 ` Gilles Chanteperdrix 0 siblings, 1 reply; 2+ messages in thread From: Jan Kiszka @ 2008-11-16 10:35 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai-core [-- Attachment #1: Type: text/plain, Size: 713 bytes --] Gilles Chanteperdrix wrote: > Author: gch > Date: Sun Nov 16 03:30:40 2008 > New Revision: 4392 > > URL: http://svn.gna.org/viewcvs/xenomai?rev=4392&view=rev > Log: > Implement nodiv_ullimd on x86_64 > > Modified: > trunk/include/asm-x86/arith_64.h Nice. This solves the user-triggerable kernel oops due to idiv overflows in the original version (rt_task_sleep_until(1LL<<63);). I happened to receive such a bug report on Friday and was about to consider alternative solutions beyond limit checks. But how accurate is this conversion? I mean how many bits can we lose when doing xnarch_ns_to_tsc(xnarch_tsc_to_ns(x))? Final question: Already prepared a 32-bit version? :) Jan [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 257 bytes --] ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [Xenomai-core] [Xenomai-commits] r4392 - /trunk/include/asm-x86/arith_64.h 2008-11-16 10:35 ` [Xenomai-core] [Xenomai-commits] r4392 - /trunk/include/asm-x86/arith_64.h Jan Kiszka @ 2008-11-16 12:13 ` Gilles Chanteperdrix 0 siblings, 0 replies; 2+ messages in thread From: Gilles Chanteperdrix @ 2008-11-16 12:13 UTC (permalink / raw) To: Jan Kiszka; +Cc: xenomai-core Jan Kiszka wrote: > Gilles Chanteperdrix wrote: >> Author: gch >> Date: Sun Nov 16 03:30:40 2008 >> New Revision: 4392 >> >> URL: http://svn.gna.org/viewcvs/xenomai?rev=4392&view=rev >> Log: >> Implement nodiv_ullimd on x86_64 >> >> Modified: >> trunk/include/asm-x86/arith_64.h > > Nice. This solves the user-triggerable kernel oops due to idiv overflows > in the original version (rt_task_sleep_until(1LL<<63);). I happened to > receive such a bug report on Friday and was about to consider > alternative solutions beyond limit checks. > > But how accurate is this conversion? I mean how many bits can we lose > when doing xnarch_ns_to_tsc(xnarch_tsc_to_ns(x))? Thanks to a little addition, nodiv_ullimd has the same precision as ullimd. > > Final question: Already prepared a 32-bit version? :) Yes, the generic vercion should work, provided we implement __rthal_add96and64 which does an addl and two adcl -- Gilles. ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2008-11-16 12:13 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <E1L1XPO-0006Xh-1s@domain.hid>
2008-11-16 10:35 ` [Xenomai-core] [Xenomai-commits] r4392 - /trunk/include/asm-x86/arith_64.h Jan Kiszka
2008-11-16 12:13 ` Gilles Chanteperdrix
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.