Neeta Shivnath Pavle
2005-Dec-02 04:03 UTC
[Xen-devel] Dirtied pages in Xen''s shadow page tables
Hi All, I am trying to come up with a matrix that gives the information about the Xen''s pages that are frequently dirtied. For this, I am going to use the shadow page tables. In [unstable]/arch/x86/mm.c, it is mentioned that these is a reference counting of pages and each page has two refcounts: tot_count and type_count(line No. 29 to 45). But I didnt found these two refcounts being used anywhere else in the code. Can anybody please tell me where I can find this information or guide me in appropriate direction. Thank you very much for your time and consideration. It will be a great help to me, Neeta. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Khoa Huynh
2005-Dec-02 22:35 UTC
Re: [Xen-devel] Dirtied pages in Xen''s shadow page tables
xen-devel-bounces@lists.xensource.com wrote on 12/01/2005 10:03:37 PM:> Hi All, > I am trying to come up with a matrix that gives the information > about the Xen''s pages that are frequently dirtied. For this, I am > going to use the shadow page tables. In [unstable]/arch/x86/mm.c, it > is mentioned that these is a reference counting of pages and each > page has two refcounts: tot_count and type_count(line No. 29 to 45). > But I didnt found these two refcounts being used anywhere else > in the code. Can anybody please tell me where I can find this > information or guide me in appropriate direction. > Thank you very much for your time and consideration. It will be a > great help to me, > > Neeta.For each page, there are two refcounts: the usual reference count and the type reference count. These refcounts are defined in pfn_info structure in xen/include/asm-x86/mm.h: struct pfn_info *page; page->count_info is the page reference count page->u.inuse.type_info is the page type reference count The page reference count is incremented and decremented in get_page() and put_page(), respectively. Both of these are defined in xen/include/asm-x86/mm.h. The page type reference count is incremented and decremented in get_page_type() and put_page_type(), respectively. Both of these are defined in xen/arch/x86/mm.c. In addition, in shadow page table mode, these reference counts are manipulated in shadow_get_page* () and shadow_put_page* (). Hope this helps. Thanks. Regards, Khoa _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel