From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: From: "Martin Frey" Subject: RE: how has set_pgdir been replaced in 2.4.x Date: Mon, 10 Dec 2001 13:35:19 +0100 Message-ID: <00c801c1817e$bc3b4d70$03fe13ac@scs.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit In-Reply-To: <20011210103855.A1919@redhat.com> Sender: owner-linux-mm@kvack.org Return-Path: To: "'Stephen C. Tweedie'" , 'Martin Maletinsky' Cc: linux-mm@kvack.org List-ID: Hi, >> I noticed that in the 2.4.x Linux kernel the function >set_pgdir() has gone (at least for most platforms). When >looking at code that modifies kernel page tables (e.g. >> vmalloc_area_pages) I could not figure out, how the page >global directories are kept consistent. It looks to me as if >> global page directory entries were modified in one global >page directory (the swapper_pg_dir) only. If this is the case, >I wonder how the modifications are 'propagated' >> into all the other global page directories > >They are now faulted on demand for vmalloc. The cost of manually >updating all the pgds for every vmalloc is just too expensive if >you've got tens of thousands of threads in the system. > Is there an implication on drivers, e.g. not accessing vmalloc'd memory from within a page fault handler? A page fault from a page fault handler is quite ugly... Best regards, Martin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/