minor

Signed-off-by: Cody Yu <hao.yu.cody@gmail.com>

Author: comaniac

vllm/v1/core/kv_cache_manager.py

@@ -92,10 +92,10 @@ def usage(self) -> float:
  self.num_gpu_blocks)
 
  def make_prefix_cache_stats(self) -> PrefixCacheStats:
- """Get (and reset) the prefix cache query and hit counts.
+ """Get (and reset) the prefix cache stats.
 
  Returns:
- The prefix caching stats - query count, and hit count.
+ The current prefix caching stats.
  """
  stats = self.prefix_cache_stats
  self.prefix_cache_stats = PrefixCacheStats()

vllm/v1/core/kv_cache_utils.py

@@ -40,7 +40,7 @@ class PrefixCachingMetrics:
 
  def __init__(self, interval: int = 1000):
  self.interval = interval
- # The current aggregated query total and hit.
+ # The current aggregated values.
  self.aggregated_requests = 0
  self.aggregated_query_total = 0
  self.aggregated_query_hit = 0
@@ -56,20 +56,21 @@ def observe(self, stats: PrefixCacheStats):
  When there are more than `interval` requests, the oldest set of
  requestsare removed from the metrics.
 
- Stats:
- reset: Whether reset_prefix_cache was invoked.
- requests: The number of requests in this update.
- queries: The number of queries in these requests.
- hits: The number of hits in these requests.
+ Args:
+ stats: The prefix cache stats.
  """
+ # reset_prefix_cache was invoked before the current update.
+ # Reset the metrics before aggregating the current stats.
  if stats.reset:
  self.reset()
 
+ # Update the metrics.
  self.query_queue.append((stats.requests, stats.queries, stats.hits))
  self.aggregated_requests += stats.requests
  self.aggregated_query_total += stats.queries
  self.aggregated_query_hit += stats.hits
 
+ # Remove the oldest stats if the number of requests exceeds.
  if self.aggregated_requests > self.interval:
  old_requests, old_queries, old_hits = self.query_queue.popleft()
  self.aggregated_requests -= old_requests

vllm/v1/metrics/stats.py

@@ -12,10 +12,14 @@
 @dataclass
 class PrefixCacheStats:
  """Stores prefix cache hit statistics."""
+ # Whether reset_prefix_cache was invoked.
  reset: bool = False
+ # The number of requests in this update.
  requests: int = 0
- hits: int = 0
+ # The number of queries in these requests.
  queries: int = 0
+ # The number of hits in these requests.
+ hits: int = 0
 
 
 @dataclass