From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <530256CB.6000603@arm.com> Date: Mon, 17 Feb 2014 18:36:59 +0000 From: Sudeep Holla MIME-Version: 1.0 Subject: Re: [PATCH RFC/RFT v2 3/8] s390: move cacheinfo sysfs to generic cacheinfo infrastructure References: <1391791763-28518-1-git-send-email-sudeep.holla@arm.com> <1391791763-28518-4-git-send-email-sudeep.holla@arm.com> <20140210113019.GC19013@osiris> In-Reply-To: <20140210113019.GC19013@osiris> Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Heiko Carstens Cc: Sudeep.Holla@arm.com, "linux-kernel@vger.kernel.org" , Martin Schwidefsky , "linux390@de.ibm.com" , "linux-s390@vger.kernel.org" List-ID: Hi Heiko, On 10/02/14 11:30, Heiko Carstens wrote: > On Fri, Feb 07, 2014 at 04:49:18PM +0000, Sudeep Holla wrote: >> From: Sudeep Holla >> >> This patch removes the redundant sysfs cacheinfo code by making use of >> the newly introduced generic cacheinfo infrastructure. >> >> Signed-off-by: Sudeep Holla > > [...] > >> -static ssize_t shared_cpu_map_func(struct kobject *kobj, int type, char *buf) >> -{ >> - struct cache_index_dir *index; >> - int len; >> + this_leaf->level = level + 1; >> + this_leaf->type = type; >> + this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti); >> + this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, >> + level, ti); >> + this_leaf->size = ecag(EXTRACT_SIZE, level, ti); >> + if (private) >> + cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); >> + else /* System wide */ >> + cpumask_copy(&this_leaf->shared_cpu_map, cpu_online_mask); > > FWIW, this also seems to be wrong: on s390 we only expose cpu private > caches via sysfs. Shared caches are not exposed (and simply saying they are > system wide would be wrong). > Please have a look at these two commits which should describe why things > are as they are on s390: > > 881730ad365130f64b5c70c40904b04eb3b79de3 > "s390/cache: expose cpu cache topology via sysfs" > 6668022c7bde3fdc96d3d257294a7216c7a46829 > "s390/cache: add cpu cache information to /proc/cpuinfo" > > I need your help to get few things clarified. IIUC, I see that shared caches are not exposed via sysfs but there are exposed through /proc/cpuinfo, right ? If yes, based on your above statement, shared cpus are may not be system-wide, then how can /proc/cpuinfo show shared cache info. Regards, Sudeep