From 996d5b4db4b191f2676cf8775565cab8a5e2753b Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 11 Jul 2018 14:02:24 -0700 Subject: 9p: Use a slab for allocating requests Replace the custom batch allocation with a slab. Use an IDR to store pointers to the active requests instead of an array. We don't try to handle P9_NOTAG specially; the IDR will happily shrink all the way back once the TVERSION call has completed. Link: http://lkml.kernel.org/r/20180711210225.19730-6-willy@infradead.org Signed-off-by: Matthew Wilcox Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet --- include/net/9p/client.h | 51 +++++++++---------------------------------------- 1 file changed, 9 insertions(+), 42 deletions(-) (limited to 'include/net/9p') diff --git a/include/net/9p/client.h b/include/net/9p/client.h index 0fa0fbab33b0..a4dc42c53d18 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -64,22 +64,15 @@ enum p9_trans_status { /** * enum p9_req_status_t - status of a request - * @REQ_STATUS_IDLE: request slot unused * @REQ_STATUS_ALLOC: request has been allocated but not sent * @REQ_STATUS_UNSENT: request waiting to be sent * @REQ_STATUS_SENT: request sent to server * @REQ_STATUS_RCVD: response received from server * @REQ_STATUS_FLSHD: request has been flushed * @REQ_STATUS_ERROR: request encountered an error on the client side - * - * The @REQ_STATUS_IDLE state is used to mark a request slot as unused - * but use is actually tracked by the idpool structure which handles tag - * id allocation. - * */ enum p9_req_status_t { - REQ_STATUS_IDLE, REQ_STATUS_ALLOC, REQ_STATUS_UNSENT, REQ_STATUS_SENT, @@ -92,24 +85,12 @@ enum p9_req_status_t { * struct p9_req_t - request slots * @status: status of this request slot * @t_err: transport error - * @flush_tag: tag of request being flushed (for flush requests) * @wq: wait_queue for the client to block on for this request * @tc: the request fcall structure * @rc: the response fcall structure * @aux: transport specific data (provided for trans_fd migration) * @req_list: link for higher level objects to chain requests - * - * Transport use an array to track outstanding requests - * instead of a list. While this may incurr overhead during initial - * allocation or expansion, it makes request lookup much easier as the - * tag id is a index into an array. (We use tag+1 so that we can accommodate - * the -1 tag for the T_VERSION request). - * This also has the nice effect of only having to allocate wait_queues - * once, instead of constantly allocating and freeing them. Its possible - * other resources could benefit from this scheme as well. - * */ - struct p9_req_t { int status; int t_err; @@ -117,40 +98,26 @@ struct p9_req_t { struct p9_fcall *tc; struct p9_fcall *rc; void *aux; - struct list_head req_list; }; /** * struct p9_client - per client instance state - * @lock: protect @fidlist + * @lock: protect @fids and @reqs * @msize: maximum data size negotiated by protocol - * @dotu: extension flags negotiated by protocol * @proto_version: 9P protocol version to use * @trans_mod: module API instantiated with this client + * @status: connection state * @trans: tranport instance state and API * @fids: All active FID handles - * @tagpool - transaction id accounting for session - * @reqs - 2D array of requests - * @max_tag - current maximum tag id allocated - * @name - node name used as client id + * @reqs: All active requests. + * @name: node name used as client id * * The client structure is used to keep track of various per-client * state that has been instantiated. - * In order to minimize per-transaction overhead we use a - * simple array to lookup requests instead of a hash table - * or linked list. In order to support larger number of - * transactions, we make this a 2D array, allocating new rows - * when we need to grow the total number of the transactions. - * - * Each row is 256 requests and we'll support up to 256 rows for - * a total of 64k concurrent requests per session. - * - * Bugs: duplicated data and potentially unnecessary elements. */ - struct p9_client { - spinlock_t lock; /* protect client structure */ + spinlock_t lock; unsigned int msize; unsigned char proto_version; struct p9_trans_module *trans_mod; @@ -170,10 +137,7 @@ struct p9_client { } trans_opts; struct idr fids; - - struct p9_idpool *tagpool; - struct p9_req_t *reqs[P9_ROW_MAXTAG]; - int max_tag; + struct idr reqs; char name[__NEW_UTS_LEN + 1]; }; @@ -279,4 +243,7 @@ struct p9_fid *p9_client_xattrwalk(struct p9_fid *, const char *, u64 *); int p9_client_xattrcreate(struct p9_fid *, const char *, u64, int); int p9_client_readlink(struct p9_fid *fid, char **target); +int p9_client_init(void); +void p9_client_exit(void); + #endif /* NET_9P_CLIENT_H */ -- cgit v1.2.3