From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH] performance problem with established hash Date: Fri, 27 Feb 2004 19:55:48 -0800 Sender: netdev-bounce@oss.sgi.com Message-ID: <20040227195548.210f7204.akpm@osdl.org> References: <20040228022537.GR5801@krispykreme> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com, linux-kernel@vger.kernel.org, davem@redhat.com, kenneth.w.chen@intel.com, olof@austin.ibm.com Return-path: To: Anton Blanchard In-Reply-To: <20040228022537.GR5801@krispykreme> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Anton Blanchard wrote: > > - goal = min(10UL, goal); > + goal = min(1UL << 10, goal); oops. Better fix the route cache too. I'm not sure what went wrong in there, sorry for letting that slip through. Obviously, doing if (a) foo = bar; else foo = zot; if (b) foo = rab; else foo = toz; does not make a ton of sense. This should fix it up. We keep the table sizing identical to that which we had in 2.6.earlier, with a boot option override. net/ipv4/route.c | 4 +--- net/ipv4/tcp.c | 4 +--- 2 files changed, 2 insertions(+), 6 deletions(-) diff -puN net/ipv4/route.c~ip_rt_init-sizing-fix net/ipv4/route.c --- 25/net/ipv4/route.c~ip_rt_init-sizing-fix 2004-02-27 19:43:01.000000000 -0800 +++ 25-akpm/net/ipv4/route.c 2004-02-27 19:51:02.000000000 -0800 @@ -2753,9 +2753,7 @@ int __init ip_rt_init(void) panic("IP: failed to allocate ip_dst_cache\n"); goal = num_physpages >> (26 - PAGE_SHIFT); - if (!rhash_entries) - goal = min(10, goal); - else + if (rhash_entries) goal = (rhash_entries * sizeof(struct rt_hash_bucket)) >> PAGE_SHIFT; for (order = 0; (1UL << order) < goal; order++) /* NOTHING */; diff -puN net/ipv4/tcp.c~ip_rt_init-sizing-fix net/ipv4/tcp.c --- 25/net/ipv4/tcp.c~ip_rt_init-sizing-fix 2004-02-27 19:51:40.000000000 -0800 +++ 25-akpm/net/ipv4/tcp.c 2004-02-27 19:52:27.000000000 -0800 @@ -2621,9 +2621,7 @@ void __init tcp_init(void) else goal = num_physpages >> (23 - PAGE_SHIFT); - if (!thash_entries) - goal = min(10UL, goal); - else + if (thash_entries) goal = (thash_entries * sizeof(struct tcp_ehash_bucket)) >> PAGE_SHIFT; for (order = 0; (1UL << order) < goal; order++) ; _