Re: [PATCH v2 1/4] lib/rhashtable: simplify bucket_table_alloc()

[Davidlohr Bueso <dave@stgolabs.net>]

Cc'ing Neil.

On Fri, 22 Jun 2018, Davidlohr Bueso wrote:

>As of ce91f6ee5b3 (mm: kvmalloc does not fallback to vmalloc for incompatible gfp flag),
>we can simplify the caller and trust kvzalloc() to just do the right thing. For the
>case of the GFP_ATOMIC context, we can drop the __GFP_NORETRY flag for obvious reasons,
>and for the __GFP_NOWARN case, however, it is changed such that the caller passes the
>flag instead of making bucket_table_alloc() handle it.
>
>This slightly changes the gfp flags passed on to nested_table_alloc() as it will now
>also use GFP_ATOMIC | __GFP_NOWARN. However, I consider this a positive consequence
>as for the same reasons we want nowarn semantics in bucket_table_alloc().
>
>Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
>---
>
>v2:
>- Changes based on Neil's concerns about keeping nowarn flag.
>- Better changelog.
>
>
>lib/rhashtable.c | 7 ++-----
>1 file changed, 2 insertions(+), 5 deletions(-)
>
>diff --git a/lib/rhashtable.c b/lib/rhashtable.c
>index 9427b5766134..083f871491a1 100644
>--- a/lib/rhashtable.c
>+++ b/lib/rhashtable.c
>@@ -175,10 +175,7 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
>	int i;
>
>	size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]);
>-	if (gfp != GFP_KERNEL)
>-		tbl = kzalloc(size, gfp | __GFP_NOWARN | __GFP_NORETRY);
>-	else
>-		tbl = kvzalloc(size, gfp);
>+	tbl = kvzalloc(size, gfp);
>
>	size = nbuckets;
>
>@@ -459,7 +456,7 @@ static int rhashtable_insert_rehash(struct rhashtable *ht,
>
>	err = -ENOMEM;
>
>-	new_tbl = bucket_table_alloc(ht, size, GFP_ATOMIC);
>+	new_tbl = bucket_table_alloc(ht, size, GFP_ATOMIC | __GFP_NOWARN);
>	if (new_tbl == NULL)
>		goto fail;
>
>-- 
>2.16.4
>