Why do flush page cache twice when change TT's cache attribute
Scott Fang
donnie.fang at gmail.com
Mon Mar 19 08:13:36 PDT 2012
typo error. abundant=>redundant
2012/3/19 Scott Fang <donnie.fang at gmail.com>
> In function ttm_tt_set_caching
> ,,,,,,,
>
> if (ttm->caching_state == tt_cached)
> drm_clflush_pages(ttm->pages, ttm->num_pages);
>
> for (i = 0; i < ttm->num_pages; ++i) {
> cur_page = ttm->pages[i];
> if (likely(cur_page != NULL)) {
> ret = ttm_tt_set_page_caching(cur_page,
> ttm->caching_state,
> c_state);
> if (unlikely(ret != 0))
> goto out_err;
> }
> }
>
> ttm->caching_state = c_state;
>
> return 0;
>
>
> drm_clflush_pages flush cache one time.
> then in the following function ttm_tt_set_page_caching->set_memory_wc->change_page_attr_set:
> in this function may flush page cache again.
>
> Does the code do some redundant flush, or there is some trick to these
> codes?
>
> Thanks for the answer in advance.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20120319/6b818b39/attachment.html>
More information about the dri-devel
mailing list