lkml.org 
[lkml]   [2010]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 01/11] mm,migration: Take a reference to the anon_vma before migrating
Date
>  rcu_unlock:
> +
> + /* Drop an anon_vma reference if we took one */
> + if (anon_vma && atomic_dec_and_lock(&anon_vma->migrate_refcount, &anon_vma->lock)) {
> + int empty = list_empty(&anon_vma->head);
> + spin_unlock(&anon_vma->lock);
> + if (empty)
> + anon_vma_free(anon_vma);
> + }
> +

Why don't we check ksm_refcount here? Also, why drop_anon_vma() doesn't
need check migrate_refcount?

plus, if we add this logic, we can remove SLAB_DESTROY_BY_RCU from
anon_vma_cachep and rcu_read_lock() from unmap_and_move(), I think.
It is for preventing anon_vma recycle logic. but no free directly mean
no memory recycle.





\
 
 \ /
  Last update: 2010-03-17 02:47    [W:0.340 / U:6.932 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site