Changeset 183261 in webkit

Timestamp:

Apr 24, 2015 4:20:10 AM (9 years ago)

Author:

Antti Koivisto

Message:

Memory cache live resources repeatedly purged during painting
​https://bugs.webkit.org/show_bug.cgi?id=144104
Source/WebCore:

<rdar://problem/20667695>

Reviewed by Chris Dumez.

On some PLT pages (like nytimes.com) we get into state where painting repeatedly purges live bitmaps.
This slows down page loads significantly.

This might have regressed because improvements in page caching keep more pages and so resources 'live'.

With this path we do all regular cache pruning asynchronously. If memory is really critical
the low memory handling code will still prune synchronously.

• loader/cache/CachedResource.cpp:

(WebCore::CachedResource::removeClient):
(WebCore::CachedResource::didAccessDecodedData):

prune() -> pruneSoon()

• loader/cache/MemoryCache.cpp:

Decrease the pruning size target from 0.95 to 0.8 so we don't need to prune so often.

(WebCore::MemoryCache::needsPruning):

Factor into a function.

(WebCore::MemoryCache::prune):
(WebCore::MemoryCache::pruneSoon):

Prune asynchronously.

• loader/cache/MemoryCache.h:

LayoutTests:

Reviewed by Chris Dumez.

• http/tests/cache/disk-cache/disk-cache-vary-cookie.html:

These clearMemoryCache calls are now done by cache-test.js.

• http/tests/cache/disk-cache/resources/cache-test.js:

(loadResources):

Make sure to clear the memory cache explicitly in the beginning so we always hit the disk cache.

(runTests):

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/http/tests/cache/disk-cache/disk-cache-vary-cookie.html (modified) (1 diff)
• LayoutTests/http/tests/cache/disk-cache/resources/cache-test.js (modified) (2 diffs)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/loader/cache/CachedResource.cpp (modified) (2 diffs)
• Source/WebCore/loader/cache/MemoryCache.cpp (modified) (2 diffs)
• Source/WebCore/loader/cache/MemoryCache.h (modified) (4 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2015-04-24  Antti Koivisto  <antti@apple.com>
+
+        Memory cache live resources repeatedly purged during painting
+        https://bugs.webkit.org/show_bug.cgi?id=144104
+
+        Reviewed by Chris Dumez.
+
+        * http/tests/cache/disk-cache/disk-cache-vary-cookie.html:
+
+            These clearMemoryCache calls are now done by cache-test.js.
+
+        * http/tests/cache/disk-cache/resources/cache-test.js:
+        (loadResources):
+
+            Make sure to clear the memory cache explicitly in the beginning so we always hit the disk cache.
+
+        (runTests):
+
 2015-04-24  Antti Koivisto  <antti@apple.com>
 

trunk/LayoutTests/http/tests/cache/disk-cache/disk-cache-vary-cookie.html

@@ -16 +16 @@
 loadResources(tests, function () {
     printResults(tests);
-    internals.clearMemoryCache();
     debug("Loading again");
     loadResources(tests, function () {
         printResults(tests);
-        internals.clearMemoryCache();
         debug("Changing cookie and loading");
         document.cookie = "cookie=othervalue";
         loadResources(tests, function () {
             printResults(tests);
-            internals.clearMemoryCache()
             debug("Loading again");
             loadResources(tests, function () {

trunk/LayoutTests/http/tests/cache/disk-cache/resources/cache-test.js

@@ -70 +70 @@
 function loadResources(tests, completetion)
 {
+    // Otherwise we just get responses from the memory cache.
+    internals.clearMemoryCache();
+    
     var pendingCount = tests.length;
     for (var i = 0; i < tests.length; ++i) {
@@ -98 +101 @@
 {
     loadResources(tests, function () {
-        // Otherwise we just get responses from the memory cache.
-        internals.clearMemoryCache();
         // Wait a bit so things settle down in the disk cache.
         setTimeout(function () {

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-04-23  Antti Koivisto  <antti@apple.com>
+
+        Memory cache live resources repeatedly purged during painting
+        https://bugs.webkit.org/show_bug.cgi?id=144104
+        <rdar://problem/20667695>
+
+        Reviewed by Chris Dumez.
+
+        On some PLT pages (like nytimes.com) we get into state where painting repeatedly purges live bitmaps.
+        This slows down page loads significantly.
+
+        This might have regressed because improvements in page caching keep more pages and so resources 'live'.
+
+        With this path we do all regular cache pruning asynchronously. If memory is really critical
+        the low memory handling code will still prune synchronously.
+
+        * loader/cache/CachedResource.cpp:
+        (WebCore::CachedResource::removeClient):
+        (WebCore::CachedResource::didAccessDecodedData):
+
+            prune() -> pruneSoon()
+
+        * loader/cache/MemoryCache.cpp:
+
+            Decrease the pruning size target from 0.95 to 0.8 so we don't need to prune so often.
+
+        (WebCore::MemoryCache::needsPruning):
+
+            Factor into a function.
+
+        (WebCore::MemoryCache::prune):
+        (WebCore::MemoryCache::pruneSoon):
+
+            Prune asynchronously.
+
+        * loader/cache/MemoryCache.h:
+
 2015-04-24  Antti Koivisto  <antti@apple.com>
 

trunk/Source/WebCore/loader/cache/CachedResource.cpp

@@ -461 +461 @@
             memoryCache.remove(*this);
         }
-        memoryCache.prune();
+        memoryCache.pruneSoon();
     }
     // This object may be dead here.
@@ -558 +558 @@
             memoryCache.insertInLiveDecodedResourcesList(*this);
         }
-        memoryCache.prune();
+        memoryCache.pruneSoon();
     }
 }

trunk/Source/WebCore/loader/cache/MemoryCache.cpp

@@ -70 +70 @@
     , m_liveSize(0)
     , m_deadSize(0)
+    , m_pruneTimer(*this, &MemoryCache::pruneTimerFired)
 {
 }
@@ -746 +747 @@
 }
 
+bool MemoryCache::needsPruning() const
+{
+    return m_liveSize + m_deadSize > m_capacity || m_deadSize > m_maxDeadCapacity;
+}
+
 void MemoryCache::prune()
 {
-    if (m_liveSize + m_deadSize <= m_capacity && m_deadSize <= m_maxDeadCapacity) // Fast path.
+    if (!needsPruning())
         return;
         
     pruneDeadResources(); // Prune dead first, in case it was "borrowing" capacity from live.
     pruneLiveResources();
+}
+
+void MemoryCache::pruneTimerFired()
+{
+    prune();
+}
+
+void MemoryCache::pruneSoon()
+{
+     if (m_pruneTimer.isActive())
+        return;
+     if (!needsPruning())
+         return;
+     m_pruneTimer.startOneShot(0);
 }
 

trunk/Source/WebCore/loader/cache/MemoryCache.h

@@ -29 +29 @@
 #include "SecurityOriginHash.h"
 #include "SessionID.h"
+#include "Timer.h"
 #include <wtf/Forward.h>
 #include <wtf/HashMap.h>
@@ -118 +119 @@
     
     void prune();
+    void pruneSoon();
     unsigned size() const { return m_liveSize + m_deadSize; }
 
@@ -185 +187 @@
     unsigned liveCapacity() const;
     unsigned deadCapacity() const;
+    bool needsPruning() const;
+    void pruneTimerFired();
 
     CachedResource* resourceForRequestImpl(const ResourceRequest&, CachedResourceMap&);
@@ -214 +218 @@
     typedef HashMap<SessionID, std::unique_ptr<CachedResourceMap>> SessionCachedResourceMap;
     SessionCachedResourceMap m_sessionResources;
+
+    Timer m_pruneTimer;
 };