[PATCH chao/erofs-dev 5/7] staging: erofs: refine compressed pages preloading flow
chao at kernel.org
Fri Dec 7 02:36:23 AEDT 2018
On 2018-12-2 2:32, Gao Xiang wrote:
> Currently, there are two kinds of compressed pages in erofs:
> 1) file pages for the in-place decompression and
> 2) managed pages for cached decompression.
> Both are all stored in grp->compressed_page.
> For managed pages, they could already exist or could be preloaded
> in this round, including the following cases in detail:
> 1) Already valid (loaded in some previous round);
> 2) PAGE_UNALLOCATED, should be allocated at the time of submission;
> 3) Just found in the managed cache, and with an extra page ref.
> Currently, 1) and 3) can be distinguishable by lock_page and
> checking its PG_private, which is guaranteed by the reclaim path,
> but it's better to make a double check by using an extra tag.
> This patch reworks the preloading flow by introducing such a tag
> by using tagged pointer, too many #ifdefs are removed as well.
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
Reviewed-by: Chao Yu <yuchao0 at huawei.com>
More information about the Linux-erofs