>>>>> On Wed, 26 Dec 2001 01:32:21 -0200, Ralf Baechle <ralf@oss.sgi.com> said: >> In somewhere between 2.4.6 and 2.4.9, the call to flush_cache_all() >> disappered from vmalloc_area_pages(). I have a data corruption >> problem in vmalloc()ed area without this call. I think we still >> need this call. ralf> Have you ever resolved this problem? I've just doublechecked ralf> the vmalloc code and it seems as if it should be entirely safe ralf> without these two calls. The tlb is flushed on vfree so no ralf> stale entries for a vmalloc address can ever be in the tlb at ralf> vmalloc time, so this flush_tlb_all() is just an expensive nop. ralf> And the same it true for flush_cache_all() no matter if caches ralf> are physically or virtually indexed. I am still using the patch and have not tried without the two calls recently... When I found this problem, I suppose that vmalloc called after free_pages causes the data corruption. vmalloc can re-use pages freed by free_pages and it seems free_pages does not flush cache. If vmalloc is to use a page which is associated with dirty cache and has different "color", virtual aliasing happens and data may be corrupt. Is this wrong? --- Atsushi Nemoto
