rxrpc: abstract away knowledge of IDR internals

Add idr_get_cursor() / idr_set_cursor() APIs, and remove the reference
to IDR_SIZE.

Link: http://lkml.kernel.org/r/1480369871-5271-65-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox 2016-12-14 15:09:19 -08:00 committed by Linus Torvalds
parent 37f4915fef
commit 444306129a
3 changed files with 34 additions and 7 deletions

View File

@ -55,6 +55,32 @@ struct idr {
}
#define DEFINE_IDR(name) struct idr name = IDR_INIT(name)
/**
* idr_get_cursor - Return the current position of the cyclic allocator
* @idr: idr handle
*
* The value returned is the value that will be next returned from
* idr_alloc_cyclic() if it is free (otherwise the search will start from
* this position).
*/
static inline unsigned int idr_get_cursor(struct idr *idr)
{
return READ_ONCE(idr->cur);
}
/**
* idr_set_cursor - Set the current position of the cyclic allocator
* @idr: idr handle
* @val: new position
*
* The next call to idr_alloc_cyclic() will return @val if it is free
* (otherwise the search will start from this position).
*/
static inline void idr_set_cursor(struct idr *idr, unsigned int val)
{
WRITE_ONCE(idr->cur, val);
}
/**
* DOC: idr sync
* idr synchronization (stolen from radix-tree.h)

View File

@ -762,16 +762,17 @@ static const struct net_proto_family rxrpc_family_ops = {
static int __init af_rxrpc_init(void)
{
int ret = -1;
unsigned int tmp;
BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > FIELD_SIZEOF(struct sk_buff, cb));
get_random_bytes(&rxrpc_epoch, sizeof(rxrpc_epoch));
rxrpc_epoch |= RXRPC_RANDOM_EPOCH;
get_random_bytes(&rxrpc_client_conn_ids.cur,
sizeof(rxrpc_client_conn_ids.cur));
rxrpc_client_conn_ids.cur &= 0x3fffffff;
if (rxrpc_client_conn_ids.cur == 0)
rxrpc_client_conn_ids.cur = 1;
get_random_bytes(&tmp, sizeof(tmp));
tmp &= 0x3fffffff;
if (tmp == 0)
tmp = 1;
idr_set_cursor(&rxrpc_client_conn_ids, tmp);
ret = -ENOMEM;
rxrpc_call_jar = kmem_cache_create(

View File

@ -263,12 +263,12 @@ static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn)
* times the maximum number of client conns away from the current
* allocation point to try and keep the IDs concentrated.
*/
id_cursor = READ_ONCE(rxrpc_client_conn_ids.cur);
id_cursor = idr_get_cursor(&rxrpc_client_conn_ids);
id = conn->proto.cid >> RXRPC_CIDSHIFT;
distance = id - id_cursor;
if (distance < 0)
distance = -distance;
limit = round_up(rxrpc_max_client_connections, IDR_SIZE) * 4;
limit = max(rxrpc_max_client_connections * 4, 1024U);
if (distance > limit)
goto mark_dont_reuse;