From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Subject: 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@xxxxxxxxxxxxxxxxx Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Reviewed-by: David Howells <dhowells@xxxxxxxxxx> Tested-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/idr.h | 26 ++++++++++++++++++++++++++ net/rxrpc/af_rxrpc.c | 11 ++++++----- net/rxrpc/conn_client.c | 4 ++-- 3 files changed, 34 insertions(+), 7 deletions(-) diff -puN include/linux/idr.h~rxrpc-abstract-away-knowledge-of-idr-internals include/linux/idr.h --- a/include/linux/idr.h~rxrpc-abstract-away-knowledge-of-idr-internals +++ a/include/linux/idr.h @@ -56,6 +56,32 @@ 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) * diff -puN net/rxrpc/af_rxrpc.c~rxrpc-abstract-away-knowledge-of-idr-internals net/rxrpc/af_rxrpc.c --- a/net/rxrpc/af_rxrpc.c~rxrpc-abstract-away-knowledge-of-idr-internals +++ a/net/rxrpc/af_rxrpc.c @@ -762,16 +762,17 @@ static const struct net_proto_family rxr 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( diff -puN net/rxrpc/conn_client.c~rxrpc-abstract-away-knowledge-of-idr-internals net/rxrpc/conn_client.c --- a/net/rxrpc/conn_client.c~rxrpc-abstract-away-knowledge-of-idr-internals +++ a/net/rxrpc/conn_client.c @@ -263,12 +263,12 @@ static bool rxrpc_may_reuse_conn(struct * 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; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
