> On Apr 23, 2015, at 1:28 PM, Chagin Dmitry <dcha...@freebsd.org> wrote: > > On Thu, Apr 23, 2015 at 12:49:51PM -0600, Scott Long wrote: >> >>> On Apr 23, 2015, at 6:19 AM, Scott Long <scott4l...@yahoo.com> wrote: >>> >>>> >>>> On Apr 12, 2015, at 12:21 AM, Dmitry Chagin <dcha...@freebsd.org> wrote: >>>> >>>> Author: dchagin >>>> Date: Sun Apr 12 06:21:58 2015 >>>> New Revision: 281451 >>>> URL: https://svnweb.freebsd.org/changeset/base/281451 >>>> >>>> Log: >>>> Rework r281162. Indeed, the flexible array member is preferable here. >>>> >>>> Suggested by: Justin T. Gibbs >>>> >>>> MFC after: 3 days >>>> >>>> Modified: >>>> head/sys/vm/uma_core.c >>>> head/sys/vm/uma_int.h >>> >>> There???s still something wrong with this. I have a machine with 28 cores >>> (56 with hyperthreading) and 256GB of RAM, and ever since you committed >>> r281162, it panics early in boot with a failed assertion. It looks like >>> the first few members of a uma_slab_t are getting overwritten accidentally, >>> and somehow the padding of the extra member in the uma_zone_t was >>> previously protecting it. I don???t know the exact cause yet, but I must >>> ask that you revert to r281161 in HEAD and stable/10 until the problem is >>> resolved. >>> >> >> I think the problem is that the masterzone_k and masterzone_z objects that >> are statically allocated in uma_core.c no longer have space for the uz_cpu >> field, but uma_zalloc_arg() always assumes that it???s there. Early in boot >> when the ???kegs' and ???zones??? zones are being initialized, there???s >> only 1 CPU so pre-allocating 1 uz_cpu element in the uma_zone is enough. I >> can???t see any way around this without significantly changing how >> uma_zalloc_arg() treats per-cpu caches. I think it???s best to revert this >> change. >> > Hi, > they initialized in uma_startup() and not used before. > I have a private converstion with a man which stable/10 hangs in > vm_mem_init().\ > with my commit. weird. > > I do not object to revert, but give me a chance to figure out what's going on.
With INVARIANTS enabled, the system will panic. Without it, it will spin in vm_mem_init(), as you noted. Even if it’s not happening to everyone, it’s a serious problem for such a minor anticipated benefit. I must insist that it be reverted. Scott _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
