On Fri, 19 Nov 2010 12:56:53 -0800 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 19 Nov 2010 17:10:33 +0900 > KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > > > Hi, this is an updated version. > > > > No major changes from the last one except for page allocation function. > > removed RFC. > > > > Order of patches is > > > > [1/4] move some functions from memory_hotplug.c to page_isolation.c > > [2/4] search physically contiguous range suitable for big chunk alloc. > > [3/4] allocate big chunk memory based on memory hotplug(migration) technique > > [4/4] modify page allocation function. > > > > For what: > > > > I hear there is requirements to allocate a chunk of page which is larger than > > MAX_ORDER. Now, some (embeded) device use a big memory chunk. To use memory, > > they hide some memory range by boot option (mem=) and use hidden memory > > for its own purpose. But this seems a lack of feature in memory management. > > > > This patch adds > > alloc_contig_pages(start, end, nr_pages, gfp_mask) > > to allocate a chunk of page whose length is nr_pages from [start, end) > > phys address. This uses similar logic of memory-unplug, which tries to > > offline [start, end) pages. By this, drivers can allocate 30M or 128M or > > much bigger memory chunk on demand. (I allocated 1G chunk in my test). > > > > But yes, because of fragmentation, this cannot guarantee 100% alloc. > > If alloc_contig_pages() is called in system boot up or movable_zone is used, > > this allocation succeeds at high rate. > > So this is an alternatve implementation for the functionality offered > by Michal's "The Contiguous Memory Allocator framework". > Yes, this will be a backends for that kind of works. I think there are two ways to allocate contiguous pages larger than MAX_ORDER. 1) hide some memory at boot and add an another memory allocator. 2) support a range allocator as [start, end) This is an trial from 2). I used memory-hotplug technique because I know some. This patch itself has no "map" and "management" function, so it should be developped in another patch (but maybe it will be not my work.) > > I tested this on x86-64, and it seems to work as expected. But feedback from > > embeded guys are appreciated because I think they are main user of this > > function. > > From where I sit, feedback from the embedded guys is *vital*, because > they are indeed the main users. > > Michal, I haven't made a note of all the people who are interested in > and who are potential users of this code. Your patch series has a > billion cc's and is up to version 6. Could I ask that you review and > test this code, and also hunt down other people (probably at other > organisations) who can do likewise for us? Because until we hear from > those people that this work satisfies their needs, we can't really > proceed much further. > yes. please. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>