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[Xen-devel] limit of grant table entries

To: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] limit of grant table entries
From: "Lily Huang" <ushuanglily@xxxxxxxxx>
Date: Wed, 14 Jun 2006 04:05:00 -0400
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I tried to do gnttab_grant_foreign_access() to grant access of certain pages to another domain. But after my code runs for a while,
I will not be able to do gnttab_grant_foreign_access() successfully and the error code is -ENOSPC. This seems to show that grant table has no
free entries. At that time, I have call this function for 2039 times.

But question is: sometimes, my system does need to grant a lot of pages to another domain, the limit of grant table seems to be a serious limitation.

Another thing is: according to the xen code, 8 pages are used to store grant table entries. Each entry is 8 bytes long, so we should be able to allocate 4096
entries. Why I got error message when I only allocated 2039 entries?

Can someone please give me an idea on how to fix this problem? Many thanks!

-lily
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