Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 13 Mar 2003 17:33:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 13 Mar 2003 17:29:59 -0500 Received: from air-2.osdl.org ([65.172.181.6]:57002 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id ; Thu, 13 Mar 2003 17:29:25 -0500 Subject: [PATCH] (2/5) Remvoe brlock from snap and vlan From: Stephen Hemminger To: Andrew Morton , Alan Cox Cc: Linux Kernel Mailing List Content-Type: text/plain Organization: Open Source Devlopment Lab Message-Id: <1047595207.3134.104.camel@dell_ss3.pdx.osdl.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 Date: 13 Mar 2003 14:40:07 -0800 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3659 Lines: 135 Remove brlock from snap and vlan. Change in snap unregister path from earlier version to use synchronize_kernel. This code needs further testing before final 2.5 inclusion. (Kind of wonder if anyone actually ever uses this?) diff -urN -X dontdiff linux-2.5.64/net/802/psnap.c linux-2.5-nobrlock/net/802/psnap.c --- linux-2.5.64/net/802/psnap.c 2003-03-11 09:08:01.000000000 -0800 +++ linux-2.5-nobrlock/net/802/psnap.c 2003-03-12 15:34:53.000000000 -0800 @@ -21,10 +21,10 @@ #include #include #include -#include LIST_HEAD(snap_list); static struct llc_sap *snap_sap; +static spinlock_t snap_lock = SPIN_LOCK_UNLOCKED; /* * Find a snap client by matching the 5 bytes. @@ -34,17 +34,15 @@ struct list_head *entry; struct datalink_proto *proto = NULL, *p; - if (list_empty(&snap_list)) - goto out; - - list_for_each(entry, &snap_list) { + rcu_read_lock(); + list_for_each_rcu(entry, &snap_list) { p = list_entry(entry, struct datalink_proto, node); if (!memcmp(p->type, desc, 5)) { proto = p; break; } } -out: + rcu_read_unlock(); return proto; } @@ -124,8 +122,7 @@ { struct datalink_proto *proto = NULL; - br_write_lock_bh(BR_NETPROTO_LOCK); - + spin_lock_bh(&snap_lock); if (find_snap_client(desc)) goto out; @@ -135,10 +132,10 @@ proto->rcvfunc = rcvfunc; proto->header_length = 5 + 3; /* snap + 802.2 */ proto->request = snap_request; - list_add(&proto->node, &snap_list); + list_add_rcu(&proto->node, &snap_list); } out: - br_write_unlock_bh(BR_NETPROTO_LOCK); + spin_unlock_bh(&snap_lock); return proto; } @@ -147,12 +144,13 @@ */ void unregister_snap_client(struct datalink_proto *proto) { - br_write_lock_bh(BR_NETPROTO_LOCK); + spin_lock_bh(&snap_lock); + list_del_rcu(&proto->node); + spin_unlock_bh(&snap_lock); - list_del(&proto->node); + synchronize_kernel(); /* wait for RCU */ kfree(proto); - br_write_unlock_bh(BR_NETPROTO_LOCK); } MODULE_LICENSE("GPL"); diff -urN -X dontdiff linux-2.5.64/net/8021q/vlan.c linux-2.5-nobrlock/net/8021q/vlan.c --- linux-2.5.64/net/8021q/vlan.c 2003-03-11 09:08:01.000000000 -0800 +++ linux-2.5-nobrlock/net/8021q/vlan.c 2003-03-12 14:52:40.000000000 -0800 @@ -29,7 +29,6 @@ #include #include #include -#include #include #include @@ -68,7 +67,6 @@ .dev =NULL, .func = vlan_skb_recv, /* VLAN receive method */ .data = (void *)(-1), /* Set here '(void *)1' when this code can SHARE SKBs */ - .next = NULL }; /* End of global variables definitions. */ @@ -231,9 +229,11 @@ real_dev->vlan_rx_kill_vid(real_dev, vlan_id); } - br_write_lock(BR_NETPROTO_LOCK); grp->vlan_devices[vlan_id] = NULL; - br_write_unlock(BR_NETPROTO_LOCK); + + /* wait for RCU in network receive */ + smp_wmb(); + synchronize_kernel(); /* Caller unregisters (and if necessary, puts) diff -urN -X dontdiff linux-2.5.64/net/8021q/vlan_dev.c linux-2.5-nobrlock/net/8021q/vlan_dev.c --- linux-2.5.64/net/8021q/vlan_dev.c 2003-03-11 09:08:01.000000000 -0800 +++ linux-2.5-nobrlock/net/8021q/vlan_dev.c 2003-03-12 14:52:40.000000000 -0800 @@ -31,7 +31,6 @@ #include #include #include -#include #include "vlan.h" #include "vlanproc.h" - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/