Sync decompression was introduced to get rid of additional kworker scheduling overhead. But there is no such overhead in non-atomic contexts. Therefore, it should be better to turn off sync decompression to avoid the current thread waiting in z_erofs_runqueue.
Signed-off-by: Huang Jianan <[email protected]> Signed-off-by: Guo Weichao <[email protected]> Reviewed-by: Gao Xiang <[email protected]> --- fs/erofs/internal.h | 2 ++ fs/erofs/super.c | 1 + fs/erofs/zdata.c | 8 ++++++-- 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 67a7ec945686..fbc4040715be 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -50,6 +50,8 @@ struct erofs_fs_context { #ifdef CONFIG_EROFS_FS_ZIP /* current strategy of how to use managed cache */ unsigned char cache_strategy; + /* strategy of sync decompression (false - auto, true - force on) */ + bool readahead_sync_decompress; /* threshold for decompression synchronously */ unsigned int max_sync_decompress_pages; diff --git a/fs/erofs/super.c b/fs/erofs/super.c index d5a6b9b888a5..0445d09b6331 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -200,6 +200,7 @@ static void erofs_default_options(struct erofs_fs_context *ctx) #ifdef CONFIG_EROFS_FS_ZIP ctx->cache_strategy = EROFS_ZIP_CACHE_READAROUND; ctx->max_sync_decompress_pages = 3; + ctx->readahead_sync_decompress = false; #endif #ifdef CONFIG_EROFS_FS_XATTR set_opt(ctx, XATTR_USER); diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index cf2d28582c14..25a0c4890d0a 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -710,6 +710,8 @@ static void z_erofs_decompressqueue_work(struct work_struct *work); static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, bool sync, int bios) { + struct erofs_sb_info *const sbi = EROFS_SB(io->sb); + /* wake up the caller thread for sync decompression */ if (sync) { unsigned long flags; @@ -723,9 +725,10 @@ static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, if (atomic_add_return(bios, &io->pending_bios)) return; - /* Use workqueue decompression for atomic contexts only */ + /* Use workqueue and sync decompression for atomic contexts only */ if (in_atomic() || irqs_disabled()) { queue_work(z_erofs_workqueue, &io->u.work); + sbi->ctx.readahead_sync_decompress = true; return; } z_erofs_decompressqueue_work(&io->u.work); @@ -1340,7 +1343,8 @@ static void z_erofs_readahead(struct readahead_control *rac) struct erofs_sb_info *const sbi = EROFS_I_SB(inode); unsigned int nr_pages = readahead_count(rac); - bool sync = (nr_pages <= sbi->ctx.max_sync_decompress_pages); + bool sync = (sbi->ctx.readahead_sync_decompress && + nr_pages <= sbi->ctx.max_sync_decompress_pages); struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); struct page *page, *head = NULL; LIST_HEAD(pagepool); -- 2.25.1
