From mboxrd@z Thu Jan 1 00:00:00 1970 From: pravin b shelar Subject: Re: [PATCH] : bug fix in multipath drr code. Date: Tue, 24 May 2005 15:27:16 +0530 Message-ID: <4292FA7C.80308@calsoftinc.com> References: <4291CBFF.6080106@calsoftinc.com> <20050523232224.GA25349@gondor.apana.org.au> <4292CDCE.2090600@calsoftinc.com> <20050524071146.GA30995@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------090501030509050709090905" Cc: netdev@oss.sgi.com, "David S. Miller" Return-path: To: Herbert Xu In-Reply-To: <20050524071146.GA30995@gondor.apana.org.au> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org This is a multi-part message in MIME format. --------------090501030509050709090905 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Herbert Xu wrote: >On Tue, May 24, 2005 at 12:16:38PM +0530, pravin b shelar wrote: > > >In fact this whole MULTIPATHOLDROUTE thing can't possibly >work at all. I'd suggest that it be removed. > > So I think we should ignore MULTIPATHOLDROUTE flag in drr and rr multipath algorithms as done in random multipath algorithm. Attached patch does same thing. Regards, Pravin. --------------090501030509050709090905 Content-Type: text/x-patch; name="multipath-drr_rr-last_use-fix.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="multipath-drr_rr-last_use-fix.patch" Signed-off by: Pravin B. Shelar Index: linux-2.6.12-rc4/include/net/route.h =================================================================== --- linux-2.6.12-rc4.orig/include/net/route.h 2005-05-06 22:20:31.000000000 -0700 +++ linux-2.6.12-rc4/include/net/route.h 2005-05-24 02:37:10.000000000 -0700 @@ -181,9 +181,6 @@ memcpy(&fl, &(*rp)->fl, sizeof(fl)); fl.fl_ip_sport = sport; fl.fl_ip_dport = dport; -#if defined(CONFIG_IP_ROUTE_MULTIPATH_CACHED) - fl.flags |= FLOWI_FLAG_MULTIPATHOLDROUTE; -#endif ip_rt_put(*rp); *rp = NULL; return ip_route_output_flow(rp, &fl, sk, 0); Index: linux-2.6.12-rc4/net/ipv4/multipath_drr.c =================================================================== --- linux-2.6.12-rc4.orig/net/ipv4/multipath_drr.c 2005-05-06 22:20:31.000000000 -0700 +++ linux-2.6.12-rc4/net/ipv4/multipath_drr.c 2005-05-24 02:37:10.000000000 -0700 @@ -57,7 +57,6 @@ static struct multipath_device state[MULTIPATH_MAX_DEVICECANDIDATES]; static DEFINE_SPINLOCK(state_lock); -static struct rtable *last_selection = NULL; static int inline __multipath_findslot(void) { @@ -111,11 +110,6 @@ .notifier_call = drr_dev_event, }; -static void drr_remove(struct rtable *rt) -{ - if (last_selection == rt) - last_selection = NULL; -} static void drr_safe_inc(atomic_t *usecount) { @@ -144,14 +138,6 @@ int devidx = -1; int cur_min_devidx = -1; - /* if necessary and possible utilize the old alternative */ - if ((flp->flags & FLOWI_FLAG_MULTIPATHOLDROUTE) != 0 && - last_selection != NULL) { - result = last_selection; - *rp = result; - return; - } - /* 1. make sure all alt. nexthops have the same GC related data */ /* 2. determine the new candidate to be returned */ result = NULL; @@ -229,12 +215,10 @@ } *rp = result; - last_selection = result; } static struct ip_mp_alg_ops drr_ops = { .mp_alg_select_route = drr_select_route, - .mp_alg_remove = drr_remove, }; static int __init drr_init(void) @@ -244,7 +228,7 @@ if (err) return err; - err = multipath_alg_register(&drr_ops, IP_MP_ALG_RR); + err = multipath_alg_register(&drr_ops, IP_MP_ALG_DRR); if (err) goto fail; Index: linux-2.6.12-rc4/net/ipv4/multipath_rr.c =================================================================== --- linux-2.6.12-rc4.orig/net/ipv4/multipath_rr.c 2005-05-06 22:20:31.000000000 -0700 +++ linux-2.6.12-rc4/net/ipv4/multipath_rr.c 2005-05-24 02:37:10.000000000 -0700 @@ -47,29 +47,12 @@ #include #include -#define MULTIPATH_MAX_CANDIDATES 40 - -static struct rtable* last_used = NULL; - -static void rr_remove(struct rtable *rt) -{ - if (last_used == rt) - last_used = NULL; -} - static void rr_select_route(const struct flowi *flp, struct rtable *first, struct rtable **rp) { struct rtable *nh, *result, *min_use_cand = NULL; int min_use = -1; - /* if necessary and possible utilize the old alternative */ - if ((flp->flags & FLOWI_FLAG_MULTIPATHOLDROUTE) != 0 && - last_used != NULL) { - result = last_used; - goto out; - } - /* 1. make sure all alt. nexthops have the same GC related data * 2. determine the new candidate to be returned */ @@ -90,15 +73,12 @@ if (!result) result = first; -out: - last_used = result; result->u.dst.__use++; *rp = result; } static struct ip_mp_alg_ops rr_ops = { .mp_alg_select_route = rr_select_route, - .mp_alg_remove = rr_remove, }; static int __init rr_init(void) --------------090501030509050709090905--