Hi Kirill, On 23 January 2015 at 12:22, Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote: > On Fri, Jan 23, 2015 at 12:37:06PM -0600, Nishanth Menon wrote: >> On 09:39-20150123, Tyler Baker wrote: >> > Hi, >> > >> > On 23 January 2015 at 09:27, Nishanth Menon <nm@xxxxxx> wrote: >> > > On 16:05-20150120, Kirill A. Shutemov wrote: >> > > [..] >> > >> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> >> > >> Reported-by: Nishanth Menon <nm@xxxxxx> >> > > Just to close on this thread: >> > > https://github.com/nmenon/kernel-test-logs/tree/next-20150123 looks good >> > > and back to old status. Thank you folks for all the help. >> > >> > I just reviewed the boot logs for next-20150123 and there still seems >> > to be a related issue. I've been boot testing >> > multi_v7_defconfig+CONFIG_ARM_LPAE=y kernel configurations which still >> > seem broken. >> > >> > For example here are two boots with exynos5250-arndale, one with >> > multi_v7_defconfig+CONFIG_ARM_LPAE=y [1] and the other with >> > multi_v7_defconfig[2]. You can see the kernel configurations with >> > CONFIG_ARM_LPAE=y show the splat: >> > >> > [ 14.605950] ------------[ cut here ]------------ >> > [ 14.609163] WARNING: CPU: 1 PID: 63 at ../mm/mmap.c:2858 >> > exit_mmap+0x1b8/0x224() >> > [ 14.616548] Modules linked in: >> > [ 14.619553] CPU: 1 PID: 63 Comm: init Not tainted 3.19.0-rc5-next-20150123 #1 >> > [ 14.626713] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) >> > [ 14.632830] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) >> > [ 14.640473] [] (show_stack) from [] (dump_stack+0x78/0x94) >> > [ 14.647678] [] (dump_stack) from [] (warn_slowpath_common+0x74/0xb0) >> > [ 14.655744] [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) >> > [ 14.664510] [] (warn_slowpath_null) from [] (exit_mmap+0x1b8/0x224) >> > [ 14.672497] [] (exit_mmap) from [] (mmput+0x40/0xf8) >> > [ 14.679180] [] (mmput) from [] (flush_old_exec+0x328/0x604) >> > [ 14.686471] [] (flush_old_exec) from [] (load_elf_binary+0x26c/0x11f4) >> > [ 14.694715] [] (load_elf_binary) from [] (search_binary_handler+0x98/0x244) >> > [ 14.703395] [] (search_binary_handler) from [] >> > (do_execveat_common+0x4dc/0x5bc) >> > [ 14.712421] [] (do_execveat_common) from [] (do_execve+0x28/0x30) >> > [ 14.720235] [] (do_execve) from [] (ret_fast_syscall+0x0/0x34) >> > [ 14.727782] ---[ end trace 5e3ca48b454c7e0a ]--- >> > [ 14.733758] ------------[ cut here ]------------ >> > >> > Has anyone else tested with CONFIG_ARM_LPAE=y that can confirm my findings? >> Uggh... I missed since i was looking at non LPAE omap2plus_defconfig. >> >> Dual A15 OMAP5432 with multi_v7_defconfig + CONFIG_ARM_LPAE=y >> https://github.com/nmenon/kernel-test-logs/blob/next-20150123/multi_lpae_defconfig/omap5-evm.txt >> >> Dual A15 DRA7/AM572x with same configuration as above. >> https://raw.githubusercontent.com/nmenon/kernel-test-logs/next-20150123/multi_lpae_defconfig/dra7xx-evm.txt >> https://github.com/nmenon/kernel-test-logs/blob/next-20150123/multi_lpae_defconfig/am57xx-evm.txt >> >> Single A15 DRA72 with same configuration as above: >> https://raw.githubusercontent.com/nmenon/kernel-test-logs/next-20150123/multi_lpae_defconfig/dra72x-evm.txt >> >> You are right. the issue re-appears with LPAE on :( >> Apologies on missing that. > > Guys, could you instrument mm_{inc,dec}_nr_pmds() with dump_stack() + > printk() of the counter and add printk() on mmap_exit() then run a simple > program which triggers the issue? For reference, here is the patch I've applied for testing, mostly stolen from Felipe's debug patch above in this thread. diff --git a/include/linux/mm.h b/include/linux/mm.h index 1fbd0e8..e5b0444 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1455,11 +1455,17 @@ static inline unsigned long mm_nr_pmds(struct mm_struct *mm) static inline void mm_inc_nr_pmds(struct mm_struct *mm) { atomic_long_inc(&mm->nr_pmds); + dump_stack(); + printk(KERN_INFO "===> %s nr_pmds %ld\n", __func__, + atomic_long_read(&mm->nr_pmds)); } static inline void mm_dec_nr_pmds(struct mm_struct *mm) { atomic_long_dec(&mm->nr_pmds); + dump_stack(); + printk(KERN_INFO "===> %s nr_pmds %ld\n", __func__, + atomic_long_read(&mm->nr_pmds)); } #endif diff --git a/mm/mmap.c b/mm/mmap.c index 6a7d36d..a16471f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2809,6 +2809,7 @@ EXPORT_SYMBOL(vm_brk); /* Release all mmaps. */ void exit_mmap(struct mm_struct *mm) { + printk(KERN_INFO "===> %s exit_mmap enter\n", __func__); struct mmu_gather tlb; struct vm_area_struct *vma; unsigned long nr_accounted = 0; I applied this patch to the tip of linux-next, configured for multi_v7_defconfig and set CONFIG_ARM_LPAE=y. The log for this arndale boot can be found here [1]. For good measure, I then rebuilt the kernel with CONFIG_ARM_LPAE=n and booted the same platform again. This log can be found here [2]. Happy hunting! > > -- > Kirill A. Shutemov [1] http://storage.kernelci.org/debug/mm/arndale-lpae-debug-next-20150123.html [2] http://storage.kernelci.org/debug/mm/arndale-no-lpae-debug-next-20150123.html Cheers, Tyler -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>