At 2025-08-29 21:08:58, "Vlastimil Babka" vbabka@suse.cz wrote:

On 8/29/25 13:29, yangshiguang wrote:

...

At 2025-08-27 16:40:21, "Vlastimil Babka" vbabka@suse.cz wrote:

...

...

...

How about this?

    /* Preemption is disabled in ___slab_alloc() */

•   gfp_flags &= ~(__GFP_DIRECT_RECLAIM);
  

•   gfp_flags = (gfp_flags & ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL)) |
  

•                                   __GFP_NOWARN;
  

I'd suggest using gfp_nested_flags() and & ~(__GFP_DIRECT_RECLAIM);

However, gfp has been processed by gfp_nested_mask() in stack_depot_save_flags().

Aha, didn't notice. Good to know!

...

Still need to call here?

No then we can indeed just mask out __GFP_DIRECT_RECLAIM.

Maybe the comment could say something like:

sure. Express clearly.

/*

• Preemption is disabled in ___slab_alloc() so we need to disallow
• blocking. The flags are further adjusted by gfp_nested_mask() in
• stack_depot itself.

*/

...

set_track_prepare() ->stack_depot_save_flags()

...

...

...

-- Cheers, Harry / Hyeonggon