On Mon, 2017-08-21 at 09:50 +0200, Michal Hocko wrote: > On Sat 19-08-17 15:49:31, Abdul Haleem wrote: > > Hi Michal, > > > > 'sysctl -a' command never completes on my PowerPC machine with latest > > next kernel (As of next-20170811) > > > > Machine Type : Power8 bare-metal > > Kernel version : 4.13.0-rc4-next-20170817 > > gcc version : 4.8.5 > > > > > > command output > > -------------- > > $ sysctl -a > > [... > > vm.hugetlb_shm_group = 0 > > vm.laptop_mode = 0 > > vm.legacy_va_layout = 0 > > vm.lowmem_reserve_ratio = 256 256 32 > > vm.max_map_count = 65530 > > vm.min_free_kbytes = 6637 > > vm.min_slab_ratio = 5 > > vm.min_unmapped_ratio = 1 > > vm.mmap_min_addr = 4096 > > vm.mmap_rnd_bits = 14 > > vm.mmap_rnd_compat_bits = 7 > > vm.nr_hugepages = 0 > > vm.nr_hugepages_mempolicy = 0 > > vm.nr_overcommit_hugepages = 0 > > vm.nr_pdflush_threads = 0 > > vm.numa_zonelist_order = Node > > vm.numa_zonelist_order = e > > vm.numa_zonelist_order = ode > > vm.numa_zonelist_order = > > vm.numa_zonelist_order = de > > vm.numa_zonelist_order = Node > > vm.numa_zonelist_order = e > > vm.numa_zonelist_order = ode > > vm.numa_zonelist_order = > > vm.numa_zonelist_order = de > > vm.numa_zonelist_order = Node > > vm.numa_zonelist_order = e > > vm.numa_zonelist_order = ode > > vm.numa_zonelist_order = > > vm.numa_zonelist_order = de > > vm.numa_zonelist_order = Node > > vm.numa_zonelist_order = e > > vm.numa_zonelist_order = ode > > ....] > > > > The last string 'vm.numa_zonelist_order = ' keeps flooding the stdout > > and command never exit. > > > > A bisection resulted commit c64e09ce mm, page_alloc: rip out > > ZONELIST_ORDER_ZONE > > Yeah, my read implementation is broken. I do not update the ppos and so > the reader doesn't know it should exit. Mel was suggesting to keep the > proc_dostring but I thought I was more clever. Sigh... > > This should do the trick. Andrew, could you fold it into > mm-page_alloc-rip-out-zonelist_order_zone.patch please? > > Thanks for the report Abdul! > > --- > commit 69885605ee3ba681deb54021e3df645f46589ba1 > Author: Michal Hocko <mhocko@xxxxxxxx> > Date: Mon Aug 21 09:46:04 2017 +0200 > > mmotm: mm-page_alloc-rip-out-zonelist_order_zone-fix > > Abdul has noticed that reading sysctl vm.numa_zonelist_order > read will never terminate. This is because of > http://lkml.kernel.org/r/20170714080006.7250-2-mhocko@xxxxxxxxxx > where the reading side doesn't update ppos and so the reader will > never get 0. Return back to proc_dostring which does all the necessary > stuff. > > Reported-by: Abdul Haleem <abdhalee@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index fda9afbd14d9..e7e92c8f4883 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h Thanks for the fix Michal, the patch fixes the problem. Reported-and-Tested-by: Abdul Haleem <abdhalee@xxxxxxxxxxxxxxxxxx> -- Regard's Abdul Haleem IBM Linux Technology Centre -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
