From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4051A816.5040000@jonmasters.org> Date: Fri, 12 Mar 2004 12:07:50 +0000 From: Jon Masters MIME-Version: 1.0 To: Fillod Stephane Cc: LinuxPPC Subject: Re: uncached user space mapping with mmap() ??? References: <2C1BAF8F8E1DD611862B0002A5D4C3FC02B6CFCF@renexch3.rennes.thmulti.com> In-Reply-To: <2C1BAF8F8E1DD611862B0002A5D4C3FC02B6CFCF@renexch3.rennes.thmulti.com> Content-Type: text/plain; charset=us-ascii; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Fillod Stephane wrote: | Indeed! I should have written: | "The bigger the mmap, the better, and the "lesser" vma entries | there will be." Yes indeed. I shall try not to be such an anal pedant in future. |>Are you somehow assuming you can have variable page sizes or will |>necessarily be using BATs to map in large regions? If this is the case |>then do bear in mind the fixed 4K page size on most platforms and the |>fact that many architectures like 4xx do not have any BATs anyway. | You're right. To have less entries in the page table, we would need | variable page sizes, since 4xx does not have BAT. Hence my remark | in form of question about ability of hugetlb. The answer must | be in the archive. I would love to look at the hugetlb stuff but have not got around to it. FWIW I looked at your Wiki example of uncached access the other day and will probably send an update for a generic peekpoke utility unless someone tells me there already is one generally available. | Thanks for the correction :-) Coffee does this kind of thing so I apologise if I ever seem snappy. Robert Love must hate me by now with the list of stuff for his book! Jon. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/