Commit 4f109b06 authored by Francois Dugast's avatar Francois Dugast
Browse files

drm/xe/gt_stats: Use atomic64_t for counters 



The stats counters are now used for things like counting the VMA
bytes during page faults. During workload execution, the counter
value can grow fast and easily reach the atomic int limit, in
which case it overflows. To make this less likely to happen, push
the limit by switching to 64b atomic to store the counter value.
Overhead is very small as there are only 3 stat entries per GT as
of now, and stats are only enabled with CONFIG_DEBUG_FS.

Suggested-by: default avatarMatthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250225195902.1247100-2-francois.dugast@intel.com


Signed-off-by: default avatarFrancois Dugast <francois.dugast@intel.com>
parent 18fbd567

drivers/gpu/drm/xe/xe_gt_stats.c

+3 −3
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ void xe_gt_stats_incr(struct xe_gt *gt, const enum xe_gt_stats_id id, int incr) 
	if (id >= __XE_GT_STATS_NUM_IDS)

		return;



	atomic_add(incr, &gt->stats.counters[id]);

	atomic64_add(incr, &gt->stats.counters[id]);

}



static const char *const stat_description[__XE_GT_STATS_NUM_IDS] = {
@@ -44,8 +44,8 @@ int xe_gt_stats_print_info(struct xe_gt *gt, struct drm_printer *p) 
	enum xe_gt_stats_id id;



	for (id = 0; id < __XE_GT_STATS_NUM_IDS; ++id)

		drm_printf(p, "%s: %d\n", stat_description[id],

			   atomic_read(&gt->stats.counters[id]));

		drm_printf(p, "%s: %lld\n", stat_description[id],

			   atomic64_read(&gt->stats.counters[id]));



	return 0;

}

drivers/gpu/drm/xe/xe_gt_types.h

+1 −1
Original line number Diff line number Diff line
@@ -139,7 +139,7 @@ struct xe_gt { 
	/** @stats: GT stats */

	struct {

		/** @stats.counters: counters for various GT stats */

		atomic_t counters[__XE_GT_STATS_NUM_IDS];

		atomic64_t counters[__XE_GT_STATS_NUM_IDS];

	} stats;

#endif