wireguard-linux/fs/btrfs/zlib.c, branch jd/unified-crypt-queue

btrfs: use larger zlib buffer for s390 hardware compression

2020-01-31T18:30:40Z

In order to benefit from s390 zlib hardware compression support, increase the btrfs zlib workspace buffer size from 1 to 4 pages (if s390 zlib hardware support is enabled on the machine). This brings up to 60% better performance in hardware on s390 compared to the PAGE_SIZE buffer and much more compared to the software zlib processing in btrfs. In case of memory pressure, fall back to a single page buffer during workspace allocation. The data compressed with larger input buffers will still conform to zlib standard and thus can be decompressed also on a systems that uses only PAGE_SIZE buffer for btrfs zlib. Link: http://lkml.kernel.org/r/20200108105103.29028-1-zaslonko@linux.ibm.com Signed-off-by: Mikhail Zaslonko Reviewed-by: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: David Sterba Cc: Richard Purdie Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Eduard Shishkin Cc: Ilya Leoshkevich Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

btrfs: compression: inline free_workspace

2019-11-18T11:46:59Z

Replace indirect calls to free_workspace by switch and calls to the specific callbacks. This is mainly to get rid of the indirection due to spectre vulnerability mitigations. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: inline alloc_workspace

2019-11-18T11:46:58Z

Replace indirect calls to alloc_workspace by switch and calls to the specific callbacks. This is mainly to get rid of the indirection due to spectre vulnerability mitigations. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: pass type to btrfs_get_workspace

2019-11-18T11:46:58Z

We can infer the workspace_manager from type and the type will be used in the following patch to call a common helper for alloc_workspace. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: inline put_workspace

2019-11-18T11:46:58Z

Similar to get_workspace, majority of the callbacks is trivial, we don't gain anything by the indirection, so replace them by a switch function. Trivial callback implementations use the helper. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: inline get_workspace

2019-11-18T11:46:58Z

Majority of the callbacks is trivial, we don't gain anything by the indirection, so replace them by a switch function. ZLIB needs to adjust level in the callback and ZSTD workspace management is complex, the rest is call to the helper. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: export alloc/free/get/put callbacks of all algos

2019-11-18T11:46:58Z

The indirect calls will be replaced by a switch in compression.c. (Switch is faster than indirect calls with when Spectre mitigations are enabled). Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: inline cleanup_workspace_manager

2019-11-18T11:46:57Z

Replace loop calling to all algos with a list of direct calls to the cleanup manager callback. When that becomes trivial it is replaced by direct call to the helper. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: let workspace manager cleanup take only the type

2019-11-18T11:46:57Z

With the access to the workspace structures, we can look it up together with the compression ops inside the workspace manager cleanup helper. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: compression: inline init_workspace_manager

2019-11-18T11:46:57Z

Replace loop calling to all algos with a list of direct calls to the init manager callback. When that becomes trivial it is replaced by direct call to the helper. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba