On Tue, Oct 29, 2019 at 11:25:13PM +0200, Ville Syrjala wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > I got some khugepaged spew on a 32bit x86: > > [ 217.490026] BUG: sleeping function called from invalid context at include/linux/mmu_notifier.h:346 > [ 217.492826] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 25, name: khugepaged > [ 217.495589] INFO: lockdep is turned off. > [ 217.498371] CPU: 1 PID: 25 Comm: khugepaged Not tainted 5.4.0-rc5-elk+ #206 > [ 217.501233] Hardware name: System manufacturer P5Q-EM/P5Q-EM, BIOS 2203 07/08/2009 > [ 217.501697] Call Trace: > [ 217.501697] dump_stack+0x66/0x8e > [ 217.501697] ___might_sleep.cold.96+0x95/0xa6 > [ 217.501697] __might_sleep+0x2e/0x80 > [ 217.501697] collapse_huge_page.isra.51+0x5ac/0x1360 > [ 217.501697] ? __alloc_pages_nodemask+0xec/0xf80 > [ 217.501697] ? __alloc_pages_nodemask+0x191/0xf80 > [ 217.501697] ? trace_hardirqs_on+0x4a/0xf0 > [ 217.501697] khugepaged+0x9a9/0x20f0 > [ 217.501697] ? _raw_spin_unlock+0x21/0x30 > [ 217.501697] ? trace_hardirqs_on+0x4a/0xf0 > [ 217.501697] ? wait_woken+0xa0/0xa0 > [ 217.501697] kthread+0xf5/0x110 > [ 217.501697] ? collapse_pte_mapped_thp+0x3b0/0x3b0 > [ 217.501697] ? kthread_create_worker_on_cpu+0x20/0x20 > [ 217.501697] ret_from_fork+0x2e/0x38 > > Looks like it's due to CONFIG_HIGHPTE=y pte_offset_map()->kmap_atomic() > vs. mmu_notifier_invalidate_range_start(). Let's do the naive approach > and just reorder the two operations. > > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxxxx> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> > Cc: linux-mm@xxxxxxxxx > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> -- Kirill A. Shutemov
