net: Add chained bufferstores to dynamically create extra packets

Author: fwsGonzo

api/net/buffer_store.hpp

@@ -45,21 +45,21 @@ namespace net
     void release(void*);
 
     /** Get size of a buffer **/
-    inline size_t bufsize() const noexcept
+    size_t bufsize() const noexcept
     { return bufsize_; }
 
-    inline size_t poolsize() const noexcept
+    size_t poolsize() const noexcept
     { return poolsize_; }
 
     /** Check if a buffer belongs here */
-    inline bool is_from_pool(buffer_t addr) const noexcept
+    bool is_from_pool(buffer_t addr) const noexcept
     { return addr >= pool_begin() and addr < pool_end(); }
 
     /** Check if an address is the start of a buffer */
-    inline bool is_buffer(buffer_t addr) const noexcept
+    bool is_buffer(buffer_t addr) const noexcept
     { return (addr - pool_) % bufsize_ == 0; }
 
-    inline size_t available() const noexcept
+    size_t available() const noexcept
     { return available_.size(); }
 
     /** move this bufferstore to the current CPU **/
@@ -76,10 +76,15 @@ namespace net
       return (addr - pool_) / bufsize_;
     }
 
+    BufferStore* get_next_bufstore();
+    inline buffer_t get_buffer_directly() noexcept;
+    inline void     release_directly(buffer_t);
+
     size_t               poolsize_;
     size_t               bufsize_;
     buffer_t             pool_;
     std::vector<buffer_t> available_;
+    BufferStore*         next_;
     int                  cpu;
     static bool          smp_enabled_;
 #ifndef INCLUDEOS_SINGLE_THREADED

src/net/buffer_store.cpp

@@ -17,8 +17,6 @@
 
 //#define DEBUG
 //#undef  NO_DEBUG
-#include <debug>
-#include <cassert>
 #if !defined(__MACH__)
 #include <malloc.h>
 #else
@@ -27,16 +25,23 @@ extern void *memalign(size_t, size_t);
 #include <net/buffer_store.hpp>
 #include <kernel/syscalls.hpp>
 #include <common>
+#include <debug>
+#include <info>
+#include <cassert>
 #include <smp>
 #define PAGE_SIZE     0x1000
 
+#define ENABLE_BUFFERSTORE_CHAIN
+#define BS_CHAIN_ALLOC_PACKETS   2048
+
 namespace net {
 
   bool BufferStore::smp_enabled_ = false;
 
   BufferStore::BufferStore(size_t num, size_t bufsize) :
     poolsize_  {num * bufsize},
-    bufsize_   {bufsize}
+    bufsize_   {bufsize},
+    next_(nullptr)
   {
     assert(num != 0);
     assert(bufsize != 0);
@@ -64,6 +69,29 @@ namespace net {
     free(this->pool_);
   }
 
+  BufferStore* BufferStore::get_next_bufstore()
+  {
+#ifdef ENABLE_BUFFERSTORE_CHAIN
+    BufferStore* parent = this;
+    while (parent->next_ != nullptr) {
+        parent = parent->next_;
+        if (parent->available() != 0) return parent;
+    }
+    INFO("BufferStore", "Allocating %u new packets", BS_CHAIN_ALLOC_PACKETS);
+    parent->next_ = new BufferStore(BS_CHAIN_ALLOC_PACKETS, bufsize());
+    return parent->next_;
+#else
+    return nullptr;
+#endif
+  }
+
+  BufferStore::buffer_t BufferStore::get_buffer_directly() noexcept
+  {
+    auto addr = available_.back();
+    available_.pop_back();
+    return addr;
+  }
+
   BufferStore::buffer_t BufferStore::get_buffer()
   {
 #ifndef INCLUDEOS_SINGLE_THREADED
@@ -78,7 +106,11 @@ namespace net {
 #ifndef INCLUDEOS_SINGLE_THREADED
       if (is_locked) unlock(plock);
 #endif
-      panic("<BufferStore> Storage pool full! Don't know how to increase pool size yet.\n");
+#ifdef ENABLE_BUFFERSTORE_CHAIN
+      return get_next_bufstore()->get_buffer_directly();
+#else
+      panic("<BufferStore> Buffer pool empty! Not configured to increase pool size.\n");
+#endif
     }
 
     auto addr = available_.back();
@@ -111,6 +143,18 @@ namespace net {
       debug("released\n");
       return;
     }
+#ifdef ENABLE_BUFFERSTORE_CHAIN
+    // try to release buffer on linked bufferstore
+    BufferStore* ptr = next_;
+    while (ptr != nullptr) {
+      if (ptr->is_from_pool(buff)) {
+        debug("released on other bufferstore\n");
+        ptr->release_directly(buff);
+        return;
+      }
+      ptr = ptr->next_;
+    }
+#endif
     // buffer not owned by bufferstore, so just delete it?
     debug("deleted\n");
     delete[] buff;
@@ -119,6 +163,11 @@ namespace net {
 #endif
   }
 
+  void BufferStore::release_directly(buffer_t buffer)
+  {
+    available_.push_back(buffer);
+  }
+
   void BufferStore::move_to_this_cpu() noexcept
   {
     this->cpu = SMP::cpu_id();

test/net/integration/bufstore/service.cpp

@@ -61,28 +61,24 @@ void Service::start(const std::string&)
   packet = nullptr;
   CHECKSERT(bufstore_.available() == BUFFER_CNT, "Bufcount is now %i", BUFFER_CNT);
 
-  INFO("Test 2","Create and chain packets, release one-by-one");
+  INFO("Test 2", "Create and chain %u packets, release one-by-one", BUFFER_CNT*10);
 
   // Reinitialize the first packet
   packet = create_packet(bufstore_);
   CHECKSERT(bufstore_.available() == BUFFER_CNT - 1, "Bufcount is now %i", BUFFER_CNT - 1);
 
   // Chain
-  for (int i = 0; i < chain_size - 1; i++){
+  for (int i = 0; i < 10*BUFFER_CNT - 1; i++){
     auto chained_packet = create_packet(bufstore_);
     packet->chain(std::move(chained_packet));
-    CHECKSERT(bufstore_.available() == BUFFER_CNT - i - 2, "Bufcount is now %i", BUFFER_CNT - i - 2);
   }
 
   INFO("Test 2","Releasing packet-chain one-by-one");
 
   // Release one-by-one
   auto tail = std::move(packet);
   size_t i = 0;
-  while(tail && i < BUFFER_CNT - 1) {
-    CHECKSERT(bufstore_.available() == i,
-              "Bufcount is now %i == %i", i,
-              bufstore_.available());
+  while(tail && i < 10*BUFFER_CNT - 1) {
     tail = tail->detach_tail();
     i++;
   }