Date: Sun, 26 Jan 2014 23:40:00 -0700 From: Warner Losh <imp@bsdimp.com> To: Joe Holden <lists@rewt.org.uk> Cc: freebsd-mips@freebsd.org Subject: Re: More trapframe panics Message-ID: <C29E2318-564A-440C-9ED8-EB3641321CFA@bsdimp.com> In-Reply-To: <52E5C925.40707@rewt.org.uk> References: <52E42A1B.3040907@rewt.org.uk> <CACVs6=--Qy_8poWdHdCXYKqkO22=dvHhW8=Uma8kLR%2BhCoZDxw@mail.gmail.com> <52E524BD.7090106@rlwinm.de> <CACVs6=-_N8aPEeFT5P8aTr1hkpmBWGwCt930wsGzg4YHxr8VKg@mail.gmail.com> <453F8F8F-41E5-4640-9683-5A8553AB0822@bsdimp.com> <CACVs6=-V4jZeTUd_ncWUDKx3a6RX773nkqbqtDaQOvoX9edoLg@mail.gmail.com> <B20276B8-9753-4CA9-8DD5-060EB43F7823@bsdimp.com> <52E5C925.40707@rewt.org.uk>
next in thread | previous in thread | raw e-mail | index | archive | help
There are some ports that just trigger it built single threaded and only = that port, which is why I was looking for a quick and dirty hack... I = fear that Juli is right, though, and a real fix is needed.... Warner On Jan 26, 2014, at 7:49 PM, Joe Holden wrote: > If one doesn't try to compile multiple ports at once, it seems to = behave.. although I'm having trouble stess testing it at the moment = since national grid seem to think supplying 0-270V to my house is = acceptable (some fault or something) :P >=20 > On 27/01/2014 01:06, Warner Losh wrote: >> Yea, I'm aware of the issues. I was hoping for a quick patch to make = my Cavium machines better since I know this is an optional feature of = the R4k spec. At the time I had my head wrapped around this, it seemed = like a faster path, but there were snags in non-uniform page sizes and = alias avoidance that make make this untenable anyway... >>=20 >> Warner >>=20 >> On Jan 26, 2014, at 4:30 PM, Juli Mallett wrote: >>=20 >>> Robert Watson and someone else (IIRC) discouraged going this route = as some CPUs do not actually support every PageMask value specified for = the R4K, so it would turn into an implementation/maintenance nightmare. = Being able to fill an arbitrary number of TLB entries with kernel stack = seems just better, anyway, for, I dunno, the person who wants to run = Python in the kernel or something :) >>>=20 >>>=20 >>> On Sun, Jan 26, 2014 at 10:54 AM, Warner Losh <imp@bsdimp.com> = wrote: >>>=20 >>> On Jan 26, 2014, at 9:04 AM, Juli Mallett wrote: >>>=20 >>>> On Sun, Jan 26, 2014 at 7:07 AM, Jan Bramkamp <crest@rlwinm.de> = wrote: >>>>>=20 >>>>> Would increasing KSTACK_PAGES from two to three or four help? What = are >>>>> the trade-offs involved in choosing KSTACK_PAGES for something = like the >>>>> EdgeMax Lite? >>>>=20 >>>>=20 >>>> That's exactly what needs to happen in all 64-bit MIPS kernels. = Unlike >>>> some other architectures, KSTACK_PAGES cannot simply be increased, >>>> however. All of the code which handles loading the kernel stack = and >>>> keeping it mapped, etc., assumes that it takes up exactly one TLB = entry, >>>> i.e. 2 pages. One could simply double KSTACK_PAGES for 64-bit = builds and >>>> modify the code to support the case of 2 or 4 pages, which would = keep the >>>> code as gross as it is today and not buy much flexibility, but = might be >>>> worthwhile as a short-term fix. Being able to support arbitrary = values of >>>> KSTACK_PAGES (or at least arbitrary multiples of 2 up to the = maximum number >>>> of wired TLB entries times 2) would be better. >>>=20 >>> I hacked together a kludge that quadrupled this by going to the next = larger page size for stack pages in the TLB, but hit something ugly when = I did that... But I've lost that code, so maybe I should try again to = see if I'm more clever the second time. >>>=20 >>> This is one of the things that makes it hard to have a nice native = build server on mips64... >>>=20 >>> Warner >>>=20 >>>=20 >>=20 >> _______________________________________________ >> freebsd-mips@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-mips >> To unsubscribe, send any mail to = "freebsd-mips-unsubscribe@freebsd.org" >>=20 >=20 > _______________________________________________ > freebsd-mips@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-mips > To unsubscribe, send any mail to = "freebsd-mips-unsubscribe@freebsd.org"
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?C29E2318-564A-440C-9ED8-EB3641321CFA>