From 334636c67e86afff9334b64e942bad80bbdf869f Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 29 Nov 2016 12:10:20 +0000 Subject: [PATCH] drm/i915: Trim i915_guc_info() stack usage i915_guc_info() (part of debugfs output) tries to avoid holding struct_mutex for a long period by copying onto the stack. This causes a warning that the stack frame is massive, so stop doing that. We can even forgo holding the struct_mutex here as that doesn't serialise the values being read (and the lists used exist for the device lifetime). v2: Skip printing anything if guc->execbuf_client is disabled (avoids potential NULL dereference). Signed-off-by: Chris Wilson Link: http://patchwork.freedesktop.org/patch/msgid/20161129121024.22650-2-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_debugfs.c | 46 +++++++++++++---------------- 1 file changed, 20 insertions(+), 26 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index db53fd09f8df..144d8066eb59 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -2434,47 +2434,41 @@ static void i915_guc_client_info(struct seq_file *m, static int i915_guc_info(struct seq_file *m, void *data) { struct drm_i915_private *dev_priv = node_to_i915(m->private); - struct drm_device *dev = &dev_priv->drm; - struct intel_guc guc; - struct i915_guc_client client = {}; + const struct intel_guc *guc = &dev_priv->guc; struct intel_engine_cs *engine; enum intel_engine_id id; - u64 total = 0; - - if (!HAS_GUC_SCHED(dev_priv)) - return 0; + u64 total; - if (mutex_lock_interruptible(&dev->struct_mutex)) + if (!guc->execbuf_client) { + seq_printf(m, "GuC submission %s\n", + HAS_GUC_SCHED(dev_priv) ? + "disabled" : + "not supported"); return 0; - - /* Take a local copy of the GuC data, so we can dump it at leisure */ - guc = dev_priv->guc; - if (guc.execbuf_client) - client = *guc.execbuf_client; - - mutex_unlock(&dev->struct_mutex); + } seq_printf(m, "Doorbell map:\n"); - seq_printf(m, "\t%*pb\n", GUC_MAX_DOORBELLS, guc.doorbell_bitmap); - seq_printf(m, "Doorbell next cacheline: 0x%x\n\n", guc.db_cacheline); + seq_printf(m, "\t%*pb\n", GUC_MAX_DOORBELLS, guc->doorbell_bitmap); + seq_printf(m, "Doorbell next cacheline: 0x%x\n\n", guc->db_cacheline); - seq_printf(m, "GuC total action count: %llu\n", guc.action_count); - seq_printf(m, "GuC action failure count: %u\n", guc.action_fail); - seq_printf(m, "GuC last action command: 0x%x\n", guc.action_cmd); - seq_printf(m, "GuC last action status: 0x%x\n", guc.action_status); - seq_printf(m, "GuC last action error code: %d\n", guc.action_err); + seq_printf(m, "GuC total action count: %llu\n", guc->action_count); + seq_printf(m, "GuC action failure count: %u\n", guc->action_fail); + seq_printf(m, "GuC last action command: 0x%x\n", guc->action_cmd); + seq_printf(m, "GuC last action status: 0x%x\n", guc->action_status); + seq_printf(m, "GuC last action error code: %d\n", guc->action_err); + total = 0; seq_printf(m, "\nGuC submissions:\n"); for_each_engine(engine, dev_priv, id) { - u64 submissions = guc.submissions[id]; + u64 submissions = guc->submissions[id]; total += submissions; seq_printf(m, "\t%-24s: %10llu, last seqno 0x%08x\n", - engine->name, submissions, guc.last_seqno[id]); + engine->name, submissions, guc->last_seqno[id]); } seq_printf(m, "\t%s: %llu\n", "Total", total); - seq_printf(m, "\nGuC execbuf client @ %p:\n", guc.execbuf_client); - i915_guc_client_info(m, dev_priv, &client); + seq_printf(m, "\nGuC execbuf client @ %p:\n", guc->execbuf_client); + i915_guc_client_info(m, dev_priv, guc->execbuf_client); i915_guc_log_info(m, dev_priv); -- 2.20.1