Date: Sat, 28 Dec 2013 18:49:25 -0600 From: Alan Cox <alc@rice.edu> To: Nathan Whitehorn <nwhitehorn@freebsd.org>, Marcel Moolenaar <marcel@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r259908 - head/sys/vm Message-ID: <52BF7195.2070606@rice.edu> In-Reply-To: <52BF6699.1040006@freebsd.org> References: <201312260546.rBQ5kAoJ009798@svn.freebsd.org> <52BF6699.1040006@freebsd.org>
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On 12/28/2013 18:02, Nathan Whitehorn wrote: > On 12/26/13 00:46, Marcel Moolenaar wrote: >> Author: marcel >> Date: Thu Dec 26 05:46:10 2013 >> New Revision: 259908 >> URL: http://svnweb.freebsd.org/changeset/base/259908 >> >> Log: >> For ia64, use pmap_remove_pages() and not pmap_remove(). The problem is >> that we don't have a good way (yet) to iterate over the mapped pages by >> virtual address and simply try each page within the range. Given that we >> call pmap_remove() over the entire 2^63 bytes of address space, it takes >> a while for pmap_remove to have tried all 2^50 pages. >> By using pmap_remove_pages() we use the PV list to find all mappings. >> >> Change derived from a patch by: alc >> > Why make this ia64-specific? It seems like a potentially useful general > optimization and certainly shouldn't be harmful on other architectures. Some of the other implementations of pmap_remove_pages() have limitations that don't permit them to be used for this purpose, e.g., if (pmap != PCPU_GET(curpmap)) { printf("warning: pmap_remove_pages called with non-current pmap\n"); return; } Alan
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