On Sun, Jun 20, 2010 at 02:19:35PM +0800, Michael Kerrisk wrote: > Hi Andi, > On Sat, Jun 19, 2010 at 9:52 PM, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote: > >> .TP > >> .BR MADV_SOFT_OFFLINE " (Since Linux 2.6.33) > >> Soft offline the pages in the range specified by > >> .I addr > >> and > >> .IR length . > >> This memory of each page in the specified range is copied to a new page, > > > > Actually there are some cases where it's also dropped if it's cached page. > > > > Perhaps better would be something more fuzzy like > > > > "the contents are preserved" > > The problem to me is that this gets so fuzzy that it's hard to > understand the meaning (I imagine many readers will ask: "What does it > mean that the contents are preserved"?). Would you be able to come up > with a wording that is a little miore detailed? That is, MADV_SOFT_OFFLINE won't lose data. If a process writes "1" to some virtual address and then called madvice(MADV_SOFT_OFFLINE) on that virtual address, it can continue to read "1" from that virtual address. MADV_SOFT_OFFLINE "transparently" replaces the underlying physical page frame with a new one that contains the same data "1". The original page frame is offlined, and the new page frame may be installed lazily. Thanks, Fengguang -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>