Date: Sat, 09 Jun 2012 12:03:43 +0300 From: Mikolaj Golub <trociny@freebsd.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: Alan Cox <alc@freebsd.org>, Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl>, Robert Watson <rwatson@freebsd.org>, Ivan Voras <ivoras@freebsd.org>, freebsd-hackers@freebsd.org Subject: Re: SuperPages utilization survey Message-ID: <86obosluvk.fsf@kopusha.home.net> In-Reply-To: <20120609083822.GJ85127@deviant.kiev.zoral.com.ua> (Konstantin Belousov's message of "Sat, 9 Jun 2012 11:38:22 %2B0300") References: <jqac8f$6mn$1@dough.gmane.org> <alpine.BSF.2.00.1206011429160.20357@wojtek.tensor.gdynia.pl> <CAF-QHFXsi3SaF-rmFK-qM89LfnStKwRWN1-HRM4yg4Bt_SFAOg@mail.gmail.com> <86sje5kkl6.fsf@kopusha.home.net> <20120609083822.GJ85127@deviant.kiev.zoral.com.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, 9 Jun 2012 11:38:22 +0300 Konstantin Belousov wrote: KB> On Sat, Jun 09, 2012 at 10:31:17AM +0300, Mikolaj Golub wrote: >> >> On Fri, 1 Jun 2012 14:54:48 +0200 Ivan Voras wrote: >> >> IV> On 1 June 2012 14:35, Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl> wrote: >> >>> http://people.freebsd.org/~ivoras/stuff/spsurvey.py >> >> ... >> >> IV> If anyone posts more data, I'll analyse it. I'm more worried about the >> IV> granularity of procstat, where it marks the entire region if a single >> IV> superpage exists in it - it means any such analysis is only >> IV> approximate. >> >> Here is a patch (for kernel and procstat) that allows to see amount of pages >> mapped to superpages. >> >> http://people.freebsd.org/~trociny/procstat-superpages.cnt.1.patch >> >> Not sure it is useful enough to be committed. KB> Superpage aggregates mappings for several normal-sized pages. KB> As a consequence, when you iterate over small pages in KB> sysctl_kern_proc_vmmap(), you account each superpage as many time as KB> much constituent small pages it contains. This is exactly what my intention was to count: how much memory are handled by superpages (using normal-sized page as a measurement unit), not amount of superpages. And I think this is what Ivan wanted to know. Do you think it is better to return number of superpages? -- Mikolaj Golub
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?86obosluvk.fsf>