| Message ID | 20170704172815.26449-1-nefelim4ag@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 04, 2017 at 08:28:15PM +0300, Timofey Titovets wrote: > For now that code just return true > Later more complex heuristic code will be added > > Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com> > --- > fs/btrfs/compression.c | 22 ++++++++++++++++++++++ > fs/btrfs/compression.h | 2 ++ > fs/btrfs/inode.c | 25 ++++++++++++++++--------- > 3 files changed, 40 insertions(+), 9 deletions(-) > > diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c > index a2fad39f79ba..481e56f61461 100644 > --- a/fs/btrfs/compression.c > +++ b/fs/btrfs/compression.c > @@ -1098,3 +1098,25 @@ int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start, > > return 1; > } > + > +/* > + * Heuristic skeleton > + * For now just would be a naive and very optimistic 'return true'. > + */ > +int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end) > +{ > + u64 index = start >> PAGE_SHIFT; > + u64 end_index = end >> PAGE_SHIFT; > + struct page *page; > + int ret = 1; > + > + while (index <= end_index) { > + page = find_get_page(inode->i_mapping, index); > + kmap(page); > + kunmap(page); > + put_page(page); > + index++; > + } > + > + return ret; > +} > diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h > index 680d4265d601..259ea776c9d4 100644 > --- a/fs/btrfs/compression.h > +++ b/fs/btrfs/compression.h > @@ -93,4 +93,6 @@ struct btrfs_compress_op { > extern const struct btrfs_compress_op btrfs_zlib_compress; > extern const struct btrfs_compress_op btrfs_lzo_compress; > > +int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); > + > #endif > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 556c93060606..285e5b5eed35 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -510,15 +510,6 @@ static noinline void compress_file_range(struct inode *inode, > */ > if (inode_need_compress(inode)) { Actually, I think we should put the decision logic based on heuristic into inode_need_compress that's called from here. So, please update prototype of inode_need_compress to take start/end and call btrfs_compress_heuristic from there. > WARN_ON(pages); > - pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); > - if (!pages) { > - /* just bail out to the uncompressed code */ > - goto cont; > - } > - > - if (BTRFS_I(inode)->force_compress) > - compress_type = BTRFS_I(inode)->force_compress; > - > /* > * we need to call clear_page_dirty_for_io on each > * page in the range. Otherwise applications with the file > @@ -530,6 +521,22 @@ static noinline void compress_file_range(struct inode *inode, > */ > extent_range_clear_dirty_for_io(inode, start, end); > redirty = 1; > + > + ret = btrfs_compress_heuristic(inode, start, end); Here we're too far to skip compression, as the pages have been marked for redirtying again. The original code proceeds to compression directly. Merging the logic into inode_need_compress would also mean that it's going to be used from run_delalloc_range. This could have other implications, but I haven't looked closely. > + > + /* Heuristic say: dont try compress that */ > + if (ret == 0) > + goto cont; > + > + pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); > + if (!pages) { > + /* just bail out to the uncompressed code */ > + goto cont; > + } > + > + if (BTRFS_I(inode)->force_compress) > + compress_type = BTRFS_I(inode)->force_compress; > + > ret = btrfs_compress_pages(compress_type, > inode->i_mapping, start, > pages, > -- > 2.13.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index a2fad39f79ba..481e56f61461 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -1098,3 +1098,25 @@ int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start, return 1; } + +/* + * Heuristic skeleton + * For now just would be a naive and very optimistic 'return true'. + */ +int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end) +{ + u64 index = start >> PAGE_SHIFT; + u64 end_index = end >> PAGE_SHIFT; + struct page *page; + int ret = 1; + + while (index <= end_index) { + page = find_get_page(inode->i_mapping, index); + kmap(page); + kunmap(page); + put_page(page); + index++; + } + + return ret; +} diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index 680d4265d601..259ea776c9d4 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -93,4 +93,6 @@ struct btrfs_compress_op { extern const struct btrfs_compress_op btrfs_zlib_compress; extern const struct btrfs_compress_op btrfs_lzo_compress; +int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); + #endif diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 556c93060606..285e5b5eed35 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -510,15 +510,6 @@ static noinline void compress_file_range(struct inode *inode, */ if (inode_need_compress(inode)) { WARN_ON(pages); - pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); - if (!pages) { - /* just bail out to the uncompressed code */ - goto cont; - } - - if (BTRFS_I(inode)->force_compress) - compress_type = BTRFS_I(inode)->force_compress; - /* * we need to call clear_page_dirty_for_io on each * page in the range. Otherwise applications with the file @@ -530,6 +521,22 @@ static noinline void compress_file_range(struct inode *inode, */ extent_range_clear_dirty_for_io(inode, start, end); redirty = 1; + + ret = btrfs_compress_heuristic(inode, start, end); + + /* Heuristic say: dont try compress that */ + if (ret == 0) + goto cont; + + pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); + if (!pages) { + /* just bail out to the uncompressed code */ + goto cont; + } + + if (BTRFS_I(inode)->force_compress) + compress_type = BTRFS_I(inode)->force_compress; + ret = btrfs_compress_pages(compress_type, inode->i_mapping, start, pages,
For now that code just return true Later more complex heuristic code will be added Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com> --- fs/btrfs/compression.c | 22 ++++++++++++++++++++++ fs/btrfs/compression.h | 2 ++ fs/btrfs/inode.c | 25 ++++++++++++++++--------- 3 files changed, 40 insertions(+), 9 deletions(-)