Re: svn commit: r341682 - head/sys/sys

On Mon, Dec 10, 2018 at 09:57:08PM -0700, Scott Long wrote: > > > > On Dec 10, 2018, at 4:47 PM, Konstantin Belousov > > wrote: > > > > On Mon, Dec 10, 2018 at 02:15:20PM -0800, John Baldwin wrote: > >> On 12/8/18 7:43 PM, Warner Losh wrote: > >>> > >>> > >>> On Sat, Dec 8, 2018, 8:36 PM Kev

Re: svn commit: r341682 - head/sys/sys

In message , Warner Losh writes: >We haven't ever supported SMP on i486, to my knowledge. There were never any usable i486 SMP hardware. The i486 CPU was not designed to do SMP so getting two CPUs to talk together (IPIs and all that) required a lot of glue-logic, which never got chip-i

Re: svn commit: r341682 - head/sys/sys

On Mon, Dec 10, 2018 at 9:57 PM Scott Long wrote: > > > > On Dec 10, 2018, at 4:47 PM, Konstantin Belousov > wrote: > > > > On Mon, Dec 10, 2018 at 02:15:20PM -0800, John Baldwin wrote: > >> On 12/8/18 7:43 PM, Warner Losh wrote: > >>> > >>> > >>> On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling

Re: svn commit: r341682 - head/sys/sys

> On Dec 10, 2018, at 4:47 PM, Konstantin Belousov wrote: > > On Mon, Dec 10, 2018 at 02:15:20PM -0800, John Baldwin wrote: >> On 12/8/18 7:43 PM, Warner Losh wrote: >>> >>> >>> On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling >> wrote: >>> >>>On Sat, Dec 8, 2

Re: svn commit: r341682 - head/sys/sys

Humor me with a kernel feature that will sue 64b atomics while both instruction streams are ping ponging on the hypothetical lock because this thread is getting pretty far out there.. On Mon, Dec 10, 2018 at 5:27 PM Justin Hibbits wrote: > > > > On Mon, Dec 10, 2018, 17:57 Ian Lepore > >> On Mon,

Re: svn commit: r341682 - head/sys/sys

On Mon, Dec 10, 2018, 5:27 PM Justin Hibbits > > On Mon, Dec 10, 2018, 17:57 Ian Lepore >> On Mon, 2018-12-10 at 14:15 -0800, John Baldwin wrote: >> > On 12/8/18 7:43 PM, Warner Losh wrote: >> > > >> > > >> > > >> > > On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling > > > m

Re: svn commit: r341682 - head/sys/sys

On Mon, Dec 10, 2018, 17:57 Ian Lepore On Mon, 2018-12-10 at 14:15 -0800, John Baldwin wrote: > > On 12/8/18 7:43 PM, Warner Losh wrote: > > > > > > > > > > > > On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling > > m wrote: > > > > > > On Sat, Dec 8, 2018 at 12:09 A

Re: svn commit: r341682 - head/sys/sys

Right we are talking about a polyfill for systems that have 1-2 cores in practice. You're not going to crank high parallelism on these global locks in practice and the common lock may help performance due to cache residence for all we know. This is a lot of ballyhoo for a decision that should fav

Re: svn commit: r341682 - head/sys/sys

On Mon, 2018-12-10 at 14:15 -0800, John Baldwin wrote: > On 12/8/18 7:43 PM, Warner Losh wrote: > > > > > > > > On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling > m wrote: > > > > On Sat, Dec 8, 2018 at 12:09 AM Mateusz Guzik > m > wro

Re: svn commit: r341682 - head/sys/sys

On Mon, Dec 10, 2018 at 02:15:20PM -0800, John Baldwin wrote: > On 12/8/18 7:43 PM, Warner Losh wrote: > > > > > > On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling > wrote: > > > > On Sat, Dec 8, 2018 at 12:09 AM Mateusz Guzik > > wrote

Re: svn commit: r341682 - head/sys/sys

On 12/8/18 7:43 PM, Warner Losh wrote: > > > On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling wrote: > > On Sat, Dec 8, 2018 at 12:09 AM Mateusz Guzik > wrote: > > > > > Fully satisfying solution would be that all architectures

Re: svn commit: r341682 - head/sys/sys

On Sat, Dec 8, 2018, 8:36 PM Kevin Bowling On Sat, Dec 8, 2018 at 12:09 AM Mateusz Guzik wrote: > > > > > Fully satisfying solution would be that all architectures get 64-bit > > ops, even if in the worst case they end up taking a lock. Then > > subsystems would not have to ifdef on anything. How

Re: svn commit: r341682 - head/sys/sys

On Sat, Dec 8, 2018 at 12:09 AM Mateusz Guzik wrote: > > Fully satisfying solution would be that all architectures get 64-bit > ops, even if in the worst case they end up taking a lock. Then > subsystems would not have to ifdef on anything. However, there > was some opposition to this proposal an

Re: svn commit: r341682 - head/sys/sys

> On 12/7/18, Ian Lepore wrote: > > On Fri, 2018-12-07 at 12:05 +, Mateusz Guzik wrote: > >> Author: mjg > >> Date: Fri Dec 7 12:05:11 2018 > >> New Revision: 341682 > >> URL: https://svnweb.freebsd.org/changeset/base/341682 > >> > >> Log: > >> unr64: use locked variant if not __LP64__ > >>

Re: svn commit: r341682 - head/sys/sys

On 12/7/18, Ian Lepore wrote: > On Fri, 2018-12-07 at 12:05 +, Mateusz Guzik wrote: >> Author: mjg >> Date: Fri Dec 7 12:05:11 2018 >> New Revision: 341682 >> URL: https://svnweb.freebsd.org/changeset/base/341682 >> >> Log: >> unr64: use locked variant if not __LP64__ >> >> The current if

Re: svn commit: r341682 - head/sys/sys

On 12/7/18 10:10 AM, Ian Lepore wrote: > On Fri, 2018-12-07 at 12:05 +, Mateusz Guzik wrote: >> Author: mjg >> Date: Fri Dec  7 12:05:11 2018 >> New Revision: 341682 >> URL: https://svnweb.freebsd.org/changeset/base/341682 >> >> Log: >>   unr64: use locked variant if not __LP64__ >>    >>   The

Re: svn commit: r341682 - head/sys/sys

On Fri, 2018-12-07 at 12:05 +, Mateusz Guzik wrote: > Author: mjg > Date: Fri Dec  7 12:05:11 2018 > New Revision: 341682 > URL: https://svnweb.freebsd.org/changeset/base/341682 > > Log: >   unr64: use locked variant if not __LP64__ >    >   The current ifdefs are not sufficient to distinguish

svn commit: r341682 - head/sys/sys

Author: mjg Date: Fri Dec 7 12:05:11 2018 New Revision: 341682 URL: https://svnweb.freebsd.org/changeset/base/341682 Log: unr64: use locked variant if not __LP64__ The current ifdefs are not sufficient to distinguish 32- and 64- bit variants, which results e.g. in powerpc64 not using ato