mm/mm_init: don't cond_resched() in deferred_init_memmap_chunk() if called from defer...

mm/mm_init: don't cond_resched() in deferred_init_memmap_chunk() if called from deferred_grow_zone()

Commit 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in
deferred_grow_zone()") made deferred_grow_zone() call
deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section
with irqs disabled.  It did check for irqs_disabled() in
deferred_init_memmap_chunk() to avoid calling cond_resched().  For a
PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable
interrupt but rcu_read_lock() is called.  This leads to the following bug
report.

  BUG: sleeping function called from invalid context at mm/mm_init.c:2091
  in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 0, expected: 0
  RCU nest depth: 1, expected: 0
  3 locks held by swapper/0/1:
   #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40
   #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278
   #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408
  CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G        W           6.19.0-rc6-test #1 PREEMPT_{RT,(full)
}
  Tainted: [W]=WARN
  Call trace:
   show_stack+0x20/0x38 (C)
   dump_stack_lvl+0xdc/0xf8
   dump_stack+0x1c/0x28
   __might_resched+0x384/0x530
   deferred_init_memmap_chunk+0x560/0x688
   deferred_grow_zone+0x190/0x278
   _deferred_grow_zone+0x18/0x30
   get_page_from_freelist+0x780/0xf78
   __alloc_frozen_pages_noprof+0x1dc/0x348
   alloc_slab_page+0x30/0x110
   allocate_slab+0x98/0x2a0
   new_slab+0x4c/0x80
   ___slab_alloc+0x5a4/0x770
   __slab_alloc.constprop.0+0x88/0x1e0
   __kmalloc_node_noprof+0x2c0/0x598
   __sdt_alloc+0x3b8/0x728
   build_sched_domains+0xe0/0x1260
   sched_init_domains+0x14c/0x1c8
   sched_init_smp+0x9c/0x1d0
   kernel_init_freeable+0x218/0x358
   kernel_init+0x28/0x208
   ret_from_fork+0x10/0x20

Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly
tell it if cond_resched() is allowed or not instead of relying on some
current state information which may vary depending on the exact kernel
configuration options that are enabled.

Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com
Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()")
Signed-off-by: Waiman Long <longman@redhat.com>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: <stable@vger.kernrl.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>