Author: sephe Date: Fri Feb 26 02:26:19 2016 New Revision: 296076 URL: https://svnweb.freebsd.org/changeset/base/296076
Log: hyperv: Use atomic_fetchadd_int to get GPADL id. Reviewed by: Hongjiang Zhang <honzhan microsoft com> MFC after: 1 week Sponsored by: Microsoft OSTC Differential Revision: https://reviews.freebsd.org/D5439 Modified: head/sys/dev/hyperv/vmbus/hv_channel.c Modified: head/sys/dev/hyperv/vmbus/hv_channel.c ============================================================================== --- head/sys/dev/hyperv/vmbus/hv_channel.c Fri Feb 26 01:52:33 2016 (r296075) +++ head/sys/dev/hyperv/vmbus/hv_channel.c Fri Feb 26 02:26:19 2016 (r296076) @@ -384,17 +384,22 @@ hv_vmbus_channel_establish_gpadl( hv_vmbus_channel_msg_info* curr; uint32_t next_gpadl_handle; - next_gpadl_handle = hv_vmbus_g_connection.next_gpadl_handle; - atomic_add_int((int*) &hv_vmbus_g_connection.next_gpadl_handle, 1); + next_gpadl_handle = atomic_fetchadd_int( + &hv_vmbus_g_connection.next_gpadl_handle, 1); ret = vmbus_channel_create_gpadl_header( contig_buffer, size, &msg_info, &msg_count); - if(ret != 0) { /* if(allocation failed) return immediately */ - /* reverse atomic_add_int above */ - atomic_subtract_int((int*) - &hv_vmbus_g_connection.next_gpadl_handle, 1); - return ret; + if(ret != 0) { + /* + * XXX + * We can _not_ even revert the above incremental, + * if multiple GPADL establishments are running + * parallelly, decrement the global next_gpadl_handle + * is calling for _big_ trouble. A better solution + * is to have a 0-based GPADL id bitmap ... + */ + return ret; } sema_init(&msg_info->wait_sema, 0, "Open Info Sema"); _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
