From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nausicaa2.coritel.it (host254-130-static.190-82-b.business.telecomitalia.it [82.190.130.254]) by ozlabs.org (Postfix) with ESMTP id 5309FDE059 for ; Thu, 17 Jul 2008 19:02:25 +1000 (EST) Message-ID: <487F0B2A.5050203@coritel.it> Date: Thu, 17 Jul 2008 11:04:42 +0200 From: Marco Stornelli MIME-Version: 1.0 To: Misbah khan Subject: Re: how to allocate 9MB of memory in kernel ? References: <18503022.post@talk.nabble.com> <487EFA1E.8060804@coritel.it> <18503965.post@talk.nabble.com> In-Reply-To: <18503965.post@talk.nabble.com> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Misbah khan ha scritto: >>> You can use the mem option to tell to the kernel that you've got less >>> ram you really have. > I really didnt got the point you made. Can you please elaborate it for my > understanding. If you've got 128MB of ram you can use the mem option to tell to the kernel the it can use only (128 - 9) MB of ram, after that you can use that chunk of ram, however I think it's not the case if your goal is to use a sdram as you said in the previous message. >>> However you can read Linux device drivers chapter 8 > i dont need to allocate large memory at the boot time also vmalloc and > kmalloc i cant use as it can allocate free page up to 128kb, hence if you > could suggest me a better technique i would really appriciate . > The problem about 128KB is only for kmalloc. If I understood correctly you need only to remap the 9MB of your sdram. > ---Misbah <>< > > > Marco Stornelli wrote: >> Misbah khan ha scritto: >>> Hi all, >>> >>> I need to allocate 9 MB of memory in to the kernel space which i need to >>> mmap for the application to access. >>> >>> I need to know what could be the best possible way of doing the same. >>> >>> Please share your experience in this regard . >>> >>> Thank you in advance >>> >>> ----Misbah <>< >> You can use the mem option to tell to the kernel that you've got less >> ram you really have. However you can read Linux device drivers chapter 8 >> "Obtaining Large Buffers" :). >> >> Regards, >> >> -- >> Marco Stornelli >> Embedded Software Engineer >> CoRiTeL - Consorzio di Ricerca sulle Telecomunicazioni >> http://www.coritel.it >> >> marco.stornelli@coritel.it >> +39 06 72582838 >> _______________________________________________ >> Linuxppc-embedded mailing list >> Linuxppc-embedded@ozlabs.org >> https://ozlabs.org/mailman/listinfo/linuxppc-embedded >> >> > -- Marco Stornelli Embedded Software Engineer CoRiTeL - Consorzio di Ricerca sulle Telecomunicazioni http://www.coritel.it marco.stornelli@coritel.it +39 06 72582838