crimson/os/seastore: introduce try_reserve

Signed-off-by: Zhang Song <zhangsong325@gmail.com>

diff --git a/src/crimson/os/seastore/async_cleaner.cc b/src/crimson/os/seastore/async_cleaner.cc
index 896b6ee3a7d3d0aa129976e5978075d37ce4f1cf..b4fd2f1b3a8e42c26d703859c900b6bb139629f4 100644 (file)
--- a/src/crimson/os/seastore/async_cleaner.cc
+++ b/src/crimson/os/seastore/async_cleaner.cc
@@ -411,7 +411,8 @@ JournalTrimmerImpl::JournalTrimmerImpl(
     config(config),
     journal_type(type),
     roll_start(roll_start),
-    roll_size(roll_size)
+    roll_size(roll_size),
+    reserved_usage(0)
 {
   config.validate();
   ceph_assert(roll_start >= 0);
@@ -1504,12 +1505,18 @@ segment_id_t SegmentCleaner::get_next_reclaim_segment() const
   }
 }
 
-void SegmentCleaner::reserve_projected_usage(std::size_t projected_usage)
+bool SegmentCleaner::try_reserve_projected_usage(std::size_t projected_usage)
 {
   assert(background_callback->is_ready());
   stats.projected_used_bytes += projected_usage;
-  ++stats.projected_count;
-  stats.projected_used_bytes_sum += stats.projected_used_bytes;
+  if (should_block_io_on_clean()) {
+    stats.projected_used_bytes -= projected_usage;
+    return false;
+  } else {
+    ++stats.projected_count;
+    stats.projected_used_bytes_sum += stats.projected_used_bytes;
+    return true;
+  }
 }
 
 void SegmentCleaner::release_projected_usage(std::size_t projected_usage)
@@ -1607,10 +1614,11 @@ void RBMCleaner::commit_space_used(paddr_t addr, extent_len_t len)
   }
 }
 
-void RBMCleaner::reserve_projected_usage(std::size_t projected_usage)
+bool RBMCleaner::try_reserve_projected_usage(std::size_t projected_usage)
 {
   assert(background_callback->is_ready());
   stats.projected_used_bytes += projected_usage;
+  return true;
 }
 
 void RBMCleaner::release_projected_usage(std::size_t projected_usage)

diff --git a/src/crimson/os/seastore/async_cleaner.h b/src/crimson/os/seastore/async_cleaner.h
index 4e03980c942cc8ae96cb6deee4eab73e6662716b..d76084dea8e0f2f53cbe7b0a6f1fa1c75eaabeb8 100644 (file)
--- a/src/crimson/os/seastore/async_cleaner.h
+++ b/src/crimson/os/seastore/async_cleaner.h
@@ -426,6 +426,15 @@ public:
   virtual void update_journal_tails(
       journal_seq_t dirty_tail, journal_seq_t alloc_tail) = 0;
 
+  // try reserve the projected usage in journal
+  // returns if the reservation is successful
+  // if the reservation is successful, user should call
+  // release_inline_usage to restore.
+  virtual bool try_reserve_inline_usage(std::size_t usage) = 0;
+
+  // release the projected usage in journal
+  virtual void release_inline_usage(std::size_t usage) = 0;
+
   virtual ~JournalTrimmer() {}
 
   journal_seq_t get_journal_tail() const {
@@ -537,7 +546,24 @@ public:
   }
 
   bool should_block_io_on_trim() const {
-    return get_tail_limit() > get_journal_tail();
+    return get_tail_limit() >
+      get_journal_tail().add_offset(
+        journal_type, reserved_usage, roll_start, roll_size);
+  }
+
+  bool try_reserve_inline_usage(std::size_t usage) final {
+    reserved_usage += usage;
+    if (should_block_io_on_trim()) {
+      reserved_usage -= usage;
+      return false;
+    } else {
+      return true;
+    }
+  }
+
+  void release_inline_usage(std::size_t usage) final {
+    ceph_assert(reserved_usage >= usage);
+    reserved_usage -= usage;
   }
 
   using trim_ertr = crimson::errorator<
@@ -583,6 +609,8 @@ private:
   journal_seq_t journal_dirty_tail;
   journal_seq_t journal_alloc_tail;
 
+  std::size_t reserved_usage;
+
   seastar::metrics::metric_group metrics;
 };
 
@@ -1053,7 +1081,7 @@ public:
   }
 
   std::unique_ptr<RBMSpaceTracker> make_empty() const {
-    auto ret = std::make_unique<RBMSpaceTracker>(*this); 
+    auto ret = std::make_unique<RBMSpaceTracker>(*this);
     ret->reset();
     return ret;
   }
@@ -1093,7 +1121,11 @@ public:
 
   virtual void commit_space_used(paddr_t, extent_len_t) = 0;
 
-  virtual void reserve_projected_usage(std::size_t) = 0;
+  // try reserve the projected usage in cleaner
+  // returns if the reservation is successful
+  // if the reservation is successful, user should call
+  // release_projected_usage to restore.
+  virtual bool try_reserve_projected_usage(std::size_t) = 0;
 
   virtual void release_projected_usage(std::size_t) = 0;
 
@@ -1254,7 +1286,7 @@ public:
     mark_space_used(addr, len);
   }
 
-  void reserve_projected_usage(std::size_t) final;
+  bool try_reserve_projected_usage(std::size_t) final;
 
   void release_projected_usage(size_t) final;
 
@@ -1501,7 +1533,7 @@ private:
      * projected_used_bytes
      *
      * Sum of projected bytes used by each transaction between throttle
-     * acquisition and commit completion.  See reserve_projected_usage()
+     * acquisition and commit completion.  See try_reserve_projected_usage()
      */
     uint64_t projected_used_bytes = 0;
     uint64_t projected_count = 0;
@@ -1582,7 +1614,7 @@ public:
 
   void commit_space_used(paddr_t, extent_len_t) final;
 
-  void reserve_projected_usage(std::size_t) final;
+  bool try_reserve_projected_usage(std::size_t) final;
 
   void release_projected_usage(size_t) final;
 

diff --git a/src/crimson/os/seastore/extent_placement_manager.cc b/src/crimson/os/seastore/extent_placement_manager.cc
index 54fd44c4758dc46cb8a5c9869cfb86f86956673b..53055f2401ce2e52a3011f925c79edaa956686ee 100644 (file)
--- a/src/crimson/os/seastore/extent_placement_manager.cc
+++ b/src/crimson/os/seastore/extent_placement_manager.cc
@@ -419,47 +419,68 @@ ExtentPlacementManager::BackgroundProcess::run_until_halt()
   );
 }
 
+ExtentPlacementManager::BackgroundProcess::reserve_result_t
+ExtentPlacementManager::BackgroundProcess::try_reserve(
+    const projected_usage_t &usage)
+{
+  reserve_result_t res {
+    trimmer->try_reserve_inline_usage(usage.inline_usage),
+    cleaner->try_reserve_projected_usage(usage.inline_usage + usage.ool_usage)
+  };
+
+  if (!res.is_successful()) {
+    if (res.reserve_inline_success) {
+      trimmer->release_inline_usage(usage.inline_usage);
+    }
+    if (res.reserve_ool_success) {
+      cleaner->release_projected_usage(usage.inline_usage + usage.ool_usage);
+    }
+  }
+  return res;
+}
+
 seastar::future<>
 ExtentPlacementManager::BackgroundProcess::reserve_projected_usage(
     projected_usage_t usage)
 {
-  auto projected_usage = usage.inline_usage + usage.ool_usage;
   ceph_assert(is_ready());
   ceph_assert(!blocking_io);
   // The pipeline configuration prevents another IO from entering
   // prepare until the prior one exits and clears this.
   ++stats.io_count;
-  bool is_blocked = false;
-  if (trimmer->should_block_io_on_trim()) {
-    is_blocked = true;
-    ++stats.io_blocked_count_trim;
-  }
-  if (cleaner->should_block_io_on_clean()) {
-    is_blocked = true;
-    ++stats.io_blocked_count_clean;
-  }
-  if (is_blocked) {
+
+  auto res = try_reserve(usage);
+  if (res.is_successful()) {
+    return seastar::now();
+  } else {
+    if (!res.reserve_inline_success) {
+      ++stats.io_blocked_count_trim;
+    }
+    if (!res.reserve_ool_success) {
+      ++stats.io_blocked_count_clean;
+    }
     ++stats.io_blocking_num;
     ++stats.io_blocked_count;
     stats.io_blocked_sum += stats.io_blocking_num;
-  }
-  return seastar::do_until(
-    [this] {
-      log_state("reserve_projected_usage(await_hard_limits)");
-      return !should_block_io();
-    },
-    [this] {
+
+    return seastar::repeat([this, usage] {
       blocking_io = seastar::promise<>();
-      return blocking_io->get_future();
-    }
-  ).then([this, is_blocked, projected_usage] {
-    ceph_assert(!blocking_io);
-    if (is_blocked) {
-      assert(stats.io_blocking_num > 0);
-      --stats.io_blocking_num;
-    }
-    cleaner->reserve_projected_usage(projected_usage);
-  });
+      return blocking_io->get_future(
+      ).then([this, usage] {
+        ceph_assert(!blocking_io);
+        auto res = try_reserve(usage);
+        if (res.is_successful()) {
+          assert(stats.io_blocking_num > 0);
+          --stats.io_blocking_num;
+          return seastar::make_ready_future<seastar::stop_iteration>(
+            seastar::stop_iteration::yes);
+        } else {
+          return seastar::make_ready_future<seastar::stop_iteration>(
+            seastar::stop_iteration::no);
+        }
+      });
+    });
+  }
 }
 
 seastar::future<>

diff --git a/src/crimson/os/seastore/extent_placement_manager.h b/src/crimson/os/seastore/extent_placement_manager.h
index 412345d8dfa872328e45e0303b3920216e49e168..3297af0394f8bc671d688569a9311090462d3a38 100644 (file)
--- a/src/crimson/os/seastore/extent_placement_manager.h
+++ b/src/crimson/os/seastore/extent_placement_manager.h
@@ -464,6 +464,7 @@ private:
 
     void release_projected_usage(projected_usage_t usage) {
       ceph_assert(is_ready());
+      trimmer->release_inline_usage(usage.inline_usage);
       cleaner->release_projected_usage(usage.inline_usage + usage.ool_usage);
     }
 
@@ -536,6 +537,17 @@ private:
              cleaner->should_block_io_on_clean();
     }
 
+    struct reserve_result_t {
+      bool reserve_inline_success = true;
+      bool reserve_ool_success = true;
+
+      bool is_successful() const {
+        return reserve_inline_success && reserve_ool_success;
+      }
+    };
+
+    reserve_result_t try_reserve(const projected_usage_t &usage);
+
     seastar::future<> do_background_cycle();
 
     void register_metrics();

diff --git a/src/test/crimson/seastore/test_btree_lba_manager.cc b/src/test/crimson/seastore/test_btree_lba_manager.cc
index fc510239ac2c7e3b69b0ba64248335d48cf42af6..218f64fa06043e868bca50c56ab945e487ea72fa 100644 (file)
--- a/src/test/crimson/seastore/test_btree_lba_manager.cc
+++ b/src/test/crimson/seastore/test_btree_lba_manager.cc
@@ -61,6 +61,10 @@ struct btree_test_base :
 
   void update_journal_tails(journal_seq_t, journal_seq_t) final {}
 
+  bool try_reserve_inline_usage(std::size_t) final { return true; }
+
+  void release_inline_usage(std::size_t) final {}
+
   /*
    * SegmentProvider interfaces
    */

diff --git a/src/test/crimson/seastore/test_cbjournal.cc b/src/test/crimson/seastore/test_cbjournal.cc
index 8ae30b01387f52ee810b91440d078d12e046c433..21a66a3dd9f5590d5a7caf1f94d05f7dfb7e11f3 100644 (file)
--- a/src/test/crimson/seastore/test_cbjournal.cc
+++ b/src/test/crimson/seastore/test_cbjournal.cc
@@ -163,6 +163,10 @@ struct cbjournal_test_t : public seastar_test_suite_t, JournalTrimmer
     return seastar::now();
   }
 
+  bool try_reserve_inline_usage(std::size_t) final { return true; }
+
+  void release_inline_usage(std::size_t) final {}
+
   auto submit_record(record_t&& record) {
     entries.push_back(record);
     OrderingHandle handle = get_dummy_ordering_handle();

diff --git a/src/test/crimson/seastore/test_seastore_journal.cc b/src/test/crimson/seastore/test_seastore_journal.cc
index 7b72d7cff9ceff10bbd9b71eafb519f3e7275e1e..375e2d5b8a4bd6bf1e7e3c2531426d9ecdff7b43 100644 (file)
--- a/src/test/crimson/seastore/test_seastore_journal.cc
+++ b/src/test/crimson/seastore/test_seastore_journal.cc
@@ -100,6 +100,10 @@ struct journal_test_t : seastar_test_suite_t, SegmentProvider, JournalTrimmer {
 
   void update_journal_tails(journal_seq_t, journal_seq_t) final {}
 
+  bool try_reserve_inline_usage(std::size_t) final { return true; }
+
+  void release_inline_usage(std::size_t) final {}
+
   /*
    * SegmentProvider interfaces
    */