From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Kenneth W" Date: Sat, 26 Feb 2005 00:25:16 +0000 Subject: RE: [PATCH] random ia64 sched-domains values Message-Id: <200502260025.j1Q0PGg10838@unix-os.sc.intel.com> List-Id: References: <421EDE70.3010501@yahoo.com.au> In-Reply-To: <421EDE70.3010501@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Nick Piggin wrote on Friday, February 25, 2005 3:42 PM > >>These are some values I just found from thin-air that should > >>hopefully make ia64 work after the latest sched patches. > >> > >>+ .cache_hot_time = (10*1000000), \ > > > > > > In 2.6.9, cache_hot_time gets the value from cache_decay_tick, since > > when this become a constant again? > > > > Not sure. cache_decay_ticks isn't set to anything meaningful on > ia64 anyway. Nor i386 for that matter. This parameter is known to be sensitive for one db workload. It was discussed about 4 month back. The conclusion was that there is NO one magic constant that works for every workloads on every platforms. Until a new auto tune algorithm is written/tested, it was decided that we use cache_decay_ticks as a boot time tunable for cache_hot_time. I guess it somehow got lost soon after 2.6.9. This needs to be reinstated. Signed-off-by: Ken Chen --- linux-2.6.10/include/linux/topology.h Fri Jan 7 21:44:04 2005 +++ linux-2.6.10/include/linux/topology.h Fri Feb 25 16:02:44 2005 @@ -109,7 +109,7 @@ .max_interval = 4, \ .busy_factor = 64, \ .imbalance_pct = 125, \ - .cache_hot_time = (5*1000000/2), \ + .cache_hot_time = cache_decay_ticks*1000000 ? : (5*1000000/2),\ .cache_nice_tries = 1, \ .per_cpu_gain = 100, \ .flags = SD_LOAD_BALANCE \