From 2aea8493d326bdf15446768333e1d2c91b040b5c Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Tue, 26 Jul 2016 15:22:42 -0700 Subject: [PATCH] zram: rename zstrm find-release functions This has started as a 'add zlib support' work, but after some thinking I saw no blockers for a bigger change -- a switch to crypto API. We don't have an idle zstreams list anymore and our write path now works absolutely differently, preventing preemption during compression. This removes possibilities of read paths preempting writes at wrong places and opens the door for a move from custom LZO/LZ4 compression backends implementation to a more generic one, using crypto compress API. This patch set also eliminates the need of a new context-less crypto API interface, which was quite hard to sell, so we can move along faster. benchmarks: (x86_64, 4GB, zram-perf script) perf reported run-time fio (max jobs=3). I performed fio test with the increasing number of parallel jobs (max to 3) on a 3G zram device, using `static' data and the following crypto comp algorithms: 842, deflate, lz4, lz4hc, lzo the output was: - test running time (which can tell us what algorithms performs faster) and - zram mm_stat (which tells the compressed memory size, max used memory, etc). It's just for information. for example, LZ4HC has twice the running time of LZO, but the compressed memory size is: 23592960 vs 34603008 bytes. test-fio-zram-842 197.907655282 seconds time elapsed 201.623142884 seconds time elapsed 226.854291345 seconds time elapsed test-fio-zram-DEFLATE 253.259516155 seconds time elapsed 258.148563401 seconds time elapsed 290.251909365 seconds time elapsed test-fio-zram-LZ4 27.022598717 seconds time elapsed 29.580522717 seconds time elapsed 33.293463430 seconds time elapsed test-fio-zram-LZ4HC 56.393954615 seconds time elapsed 74.904659747 seconds time elapsed 101.940998564 seconds time elapsed test-fio-zram-LZO 28.155948075 seconds time elapsed 30.390036330 seconds time elapsed 34.455773159 seconds time elapsed zram mm_stat-s (max fio jobs=3) test-fio-zram-842 mm_stat (jobs1): 3221225472 673185792 690266112 0 690266112 0 0 mm_stat (jobs2): 3221225472 673185792 690266112 0 690266112 0 0 mm_stat (jobs3): 3221225472 673185792 690266112 0 690266112 0 0 test-fio-zram-DEFLATE mm_stat (jobs1): 3221225472 24379392 37761024 0 37761024 0 0 mm_stat (jobs2): 3221225472 24379392 37761024 0 37761024 0 0 mm_stat (jobs3): 3221225472 24379392 37761024 0 37761024 0 0 test-fio-zram-LZ4 mm_stat (jobs1): 3221225472 23592960 37761024 0 37761024 0 0 mm_stat (jobs2): 3221225472 23592960 37761024 0 37761024 0 0 mm_stat (jobs3): 3221225472 23592960 37761024 0 37761024 0 0 test-fio-zram-LZ4HC mm_stat (jobs1): 3221225472 23592960 37761024 0 37761024 0 0 mm_stat (jobs2): 3221225472 23592960 37761024 0 37761024 0 0 mm_stat (jobs3): 3221225472 23592960 37761024 0 37761024 0 0 test-fio-zram-LZO mm_stat (jobs1): 3221225472 34603008 50335744 0 50335744 0 0 mm_stat (jobs2): 3221225472 34603008 50335744 0 50335744 0 0 mm_stat (jobs3): 3221225472 34603008 50335744 0 50339840 0 0 This patch (of 8): We don't perform any zstream idle list lookup anymore, so zcomp_strm_find()/zcomp_strm_release() names are not representative. Rename to zcomp_stream_get()/zcomp_stream_put(). Link: http://lkml.kernel.org/r/20160531122017.2878-2-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zcomp.c | 4 ++-- drivers/block/zram/zcomp.h | 4 ++-- drivers/block/zram/zram_drv.c | 8 ++++---- 3 files changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index b51a816d766b..400f8267337e 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -95,12 +95,12 @@ bool zcomp_available_algorithm(const char *comp) return find_backend(comp) != NULL; } -struct zcomp_strm *zcomp_strm_find(struct zcomp *comp) +struct zcomp_strm *zcomp_stream_get(struct zcomp *comp) { return *get_cpu_ptr(comp->stream); } -void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm) +void zcomp_stream_put(struct zcomp *comp) { put_cpu_ptr(comp->stream); } diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h index ffd88cb747fe..944b8e60dd82 100644 --- a/drivers/block/zram/zcomp.h +++ b/drivers/block/zram/zcomp.h @@ -48,8 +48,8 @@ bool zcomp_available_algorithm(const char *comp); struct zcomp *zcomp_create(const char *comp); void zcomp_destroy(struct zcomp *comp); -struct zcomp_strm *zcomp_strm_find(struct zcomp *comp); -void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm); +struct zcomp_strm *zcomp_stream_get(struct zcomp *comp); +void zcomp_stream_put(struct zcomp *comp); int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm, const unsigned char *src, size_t *dst_len); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 8fcad8b761f1..9361a5db7de8 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -695,7 +695,7 @@ compress_again: goto out; } - zstrm = zcomp_strm_find(zram->comp); + zstrm = zcomp_stream_get(zram->comp); ret = zcomp_compress(zram->comp, zstrm, uncmem, &clen); if (!is_partial_io(bvec)) { kunmap_atomic(user_mem); @@ -734,7 +734,7 @@ compress_again: __GFP_NOWARN | __GFP_HIGHMEM); if (!handle) { - zcomp_strm_release(zram->comp, zstrm); + zcomp_stream_put(zram->comp); zstrm = NULL; atomic64_inc(&zram->stats.writestall); @@ -769,7 +769,7 @@ compress_again: memcpy(cmem, src, clen); } - zcomp_strm_release(zram->comp, zstrm); + zcomp_stream_put(zram->comp); zstrm = NULL; zs_unmap_object(meta->mem_pool, handle); @@ -789,7 +789,7 @@ compress_again: atomic64_inc(&zram->stats.pages_stored); out: if (zstrm) - zcomp_strm_release(zram->comp, zstrm); + zcomp_stream_put(zram->comp); if (is_partial_io(bvec)) kfree(uncmem); return ret; -- 2.20.1