On 04/03/2014 10:03 PM, John David Anglin wrote: > On 4/3/2014 3:41 PM, Helge Deller wrote: >> On 04/02/2014 11:41 PM, John David Anglin wrote: >>> On 4/2/2014 5:09 PM, Helge Deller wrote: >>>> On 04/02/2014 09:09 PM, Carlos O'Donell wrote: >>>>> On Tue, Apr 1, 2014 at 2:49 PM, Helge Deller <deller@xxxxxx> wrote: >>>>>> Yes. >>>>>> But it's not a kernel bug. Kernel 3.14 and previous stable releases are OK. >>>>>> >>>>>> I did proposed a glibc change in my previous mail (http://www.spinics.net/lists/linux-parisc/msg05384.html). >>>>>> Debian bug report with patch is here: >>>>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=741243 >>>>>> >>>>>> And this is what I proposed: >>>>>> >>>>>> A trivial FIX/workaround would be to change libc-mmap.h like this: >>>>>> #ifdef __hppa__ >>>>>> #define MAP_FIXED_ALIGNMENT 4096 >>>>>> #else >>>>>> #define MAP_FIXED_ALIGNMENT SHMLBA >>>>>> #endif >>>>>> >>>>>> That works because then the new aligned address is then the same as the original >>>>>> (the mmap call returns 4k aligned addresses, so it stays unchanged), but I'm not sure >>>>>> if such a patch would be acceptable. >>>>>> Do you have another idea/proposal? >>>>> The responsibility for fixing this falls to me, but I've been busy. >>>> No problem. >>>> >>>>> If someone wants to propose a patch for glibc please email >>>>> libc-alpha@xxxxxxxxxxxxxx, TO me, and I'll review and commit the patch >>>>> granted that you show you've done the appropriate testing. >>>>> >>>>> Otherwise I'll get to this at some point in the next couple of weeks :-( >>>> Hi Carlos, >>>> >>>> I'm not really sure if my patch is the best way to go. Technically it's correct >>>> and it's tested since all our debian buildservers currently run with this patch. >>>> But all other options would probably involve more code changes. >>>> >>>> So, I think I'm happy if you can look at it at some point when you find time. >>>> Your input would be very valuable here. >>> I'm wondering if kernel value for SHMLBA shouldn't change to PAGE_SIZE to better >>> reflect that attach addresses are page aligned. The color alignment for shared maps >>> seems a separate issue which maybe userspace doesn't need to worry about. >> I think this is a very interesting idea and it should be pretty simple! >> >> The attached patch for eglibc should resolve it. >> And the attached patch for kernel isn't necessary, but makes it clear that the colouring is important. >> I did tested the kernel patch - and it seems to work without problems. >> >> I'm not sure if this might introduce userspace compile problems though (although unlikely). > Very nice! In our current Debian eglibc build, SHMLBA is set to 4096. *No*, it's not! In current eglibc it's set to 0x00400000 That's what my eglibc-patch changes... I'm currently building a eglibc on hpviz with SHMLBA set to 4096 (__getpagesize()). > So, it should work just fine with the kernel patch. No, the kernel patch isn't necessary. Only the glibc patch. > The buildds have been running for some time > and I'm not aware of any mmap issues aside from the pthread_create ENOMEM errors. True - we need to find the cause. I just suspected the arch_get_unmapped_area() kernel functions, but they seem correct. > Do you think this helps the allocation of small maps (perl locale test bug)? No. Only my other (unfinished) patches will resolve this. Helge -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
