From: Grant Grundler <grundler@parisc-linux.org>
To: Joel Soete <soete.joel@scarlet.be>
Cc: parisc-linux <parisc-linux@parisc-linux.org>
Subject: [parisc-linux] Re: CCIO dma io_command and related io_tlb format questions.
Date: Mon, 16 Oct 2006 23:59:23 -0600 [thread overview]
Message-ID: <20061017055923.GA6055@colo.lackof.org> (raw)
In-Reply-To: <J788XR$E1A2FE043CF88207AEC13412E82258F2@scarlet.be>
On Mon, Oct 16, 2006 at 01:51:27PM +0200, Joel Soete wrote:
...
> but it seems that at in the history num_physpages (now ram size in bytes)
> was well the physical number of page:
...
> nowaday num_physpages is bytes so the comparision is eronous?
> (compare bytes against page number)
Where did you get the idea num_physpages is in bytes?
These two examples suggest it's counting PAGE_SIZE pages :
mm/slab.c: if (num_physpages > (32 << 20) >> PAGE_SHIFT)
mm/swap.c: unsigned long megs = num_physpages >> (20 - PAGE_SHIFT);
> the same way in:
> iov_order = get_order(iova_space_size << PAGE_SHIFT);
>
> iova_space_size << PAGE_SHIFT == iova_space_size * 2^PAGE_SHIFT
> == iova_space_size * PAGE_SIZE
>
> made sense when iova_space_size was a number of pages,
Look at get_order() then you'll understand why the "<< PAGE_SHIFT".
iov_order is being set to log2(iova_space_size)+1.
grant
_______________________________________________
parisc-linux mailing list
parisc-linux@lists.parisc-linux.org
http://lists.parisc-linux.org/mailman/listinfo/parisc-linux
next prev parent reply other threads:[~2006-10-17 5:59 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <J788XR$E1A2FE043CF88207AEC13412E82258F2@scarlet.be>
2006-10-16 14:37 ` [parisc-linux] Re: CCIO dma io_command and related io_tlb format questions Michael S. Zick
2006-10-17 5:59 ` Grant Grundler [this message]
[not found] <J7AHPO$ED967CCDD9E203D6968EA2045C11A08A@scarlet.be>
[not found] ` <45351637.4070604@computer.org>
2006-10-17 19:07 ` Kyle McMartin
[not found] <J70JNP$255156D3B4F90827118C5EFE40FD3ABF@scarlet.be>
2006-10-12 19:55 ` Grant Grundler
2006-10-13 10:56 ` Joel Soete
2006-10-13 16:44 ` Grant Grundler
[not found] ` <4530DF1F.5060601@scarlet.be>
2006-10-14 14:11 ` Matthew Wilcox
2006-10-14 16:40 ` Michael S. Zick
2006-10-14 23:35 ` Joel Soete
2006-10-15 3:28 ` Grant Grundler
2006-10-11 8:48 Joel Soete
2006-10-12 1:04 ` Grant Grundler
2006-10-12 3:27 ` James Bottomley
[not found] ` <4538BB5F.5040703@scarlet.be>
2006-10-20 15:50 ` Grant Grundler
2006-10-20 16:31 ` Grant Grundler
2006-10-20 17:18 ` Joel Soete
2006-10-21 6:19 ` Grant Grundler
2006-10-21 17:17 ` Joel Soete
2006-10-23 4:34 ` Grant Grundler
-- strict thread matches above, loose matches on Subject: below --
2006-10-09 9:41 [parisc-linux] " Joel Soete
2006-10-10 22:08 ` [parisc-linux] " Grant Grundler
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20061017055923.GA6055@colo.lackof.org \
--to=grundler@parisc-linux.org \
--cc=parisc-linux@parisc-linux.org \
--cc=soete.joel@scarlet.be \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox