lkml.org 
[lkml]   [2018]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 08/18] rhashtable: clean up dereference of ->future_tbl.
On Fri, Jun 01, 2018 at 02:44:09PM +1000, NeilBrown wrote:
> Using rht_dereference_bucket() to dereference
> ->future_tbl looks like a type error, and could be confusing.
> Using rht_dereference_rcu() to test a pointer for NULL
> adds an unnecessary barrier - rcu_access_pointer() is preferred
> for NULL tests when no lock is held.
>
> This uses 3 different ways to access ->future_tbl.
> - if we know the mutex is held, use rht_dereference()
> - if we don't hold the mutex, and are only testing for NULL,
> use rcu_access_pointer()
> - otherwise (using RCU protection for true dereference),
> use rht_dereference_rcu().
>
> Note that this includes a simplification of the call to
> rhashtable_last_table() - we don't do an extra dereference
> before the call any more.
>
> Signed-off-by: NeilBrown <neilb@suse.com>

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

\
 
 \ /
  Last update: 2018-06-01 18:55    [W:0.302 / U:0.760 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site