From 71ebc9a3795818eab52e81bbcbdfae130ee35d9e Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 16 May 2017 12:10:42 +0100 Subject: dma-buf/sync-file: Defer creation of sync_file->name Constructing the name takes the majority of the time for allocating a sync_file to wrap a fence, and the name is very rarely used (only via the sync_file status user interface). To reduce the impact on the common path (that of creating sync_file to pass around), defer the construction of the name until it is first used. v2: Update kerneldoc (kbuild test robot) v3: sync_debug.c was peeking at the name v4: Comment upon the potential race between two users of sync_file_get_name() and claim that such a race is below the level of notice. However, to prevent any future nuisance, use a global spinlock to serialize the assignment of the name. v5: Completely avoid the read/write race by only storing the name passed in from the user inside sync_file->user_name and passing in a buffer to dynamically construct the name otherwise. Signed-off-by: Chris Wilson Cc: Sumit Semwal Cc: Gustavo Padovan Cc: Daniel Vetter Cc: David Herrmann Reviewed-by: Daniel Vetter Signed-off-by: Gustavo Padovan Link: http://patchwork.freedesktop.org/patch/msgid/20170516111042.24719-1-chris@chris-wilson.co.uk --- drivers/dma-buf/sync_debug.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/dma-buf/sync_debug.c') diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c index a0d780ab68c3..82a6e7f6d37f 100644 --- a/drivers/dma-buf/sync_debug.c +++ b/drivers/dma-buf/sync_debug.c @@ -132,9 +132,11 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj) static void sync_print_sync_file(struct seq_file *s, struct sync_file *sync_file) { + char buf[128]; int i; - seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name, + seq_printf(s, "[%p] %s: %s\n", sync_file, + sync_file_get_name(sync_file, buf, sizeof(buf)), sync_status_str(dma_fence_get_status(sync_file->fence))); if (dma_fence_is_array(sync_file->fence)) { -- cgit v1.2.3