Changeset 194204 in webkit

Timestamp:

Dec 16, 2015 6:55:02 PM (8 years ago)

Author:

akling@apple.com

Message:

Give kernel VM some hints about non-live memory-cached resources.
<​https://webkit.org/b/152362>

Reviewed by Geoffrey Garen.

Source/WebCore:

When a file-backed CachedResource has no live clients left, and is only being kept alive
because it's cached in the MemoryCache, give the OS a hint that we probably won't need
that memory very soon.

Normally this doesn't do anything, but in case the system comes under memory pressure,
the kernel can prioritize eviction of such clean-but-unneeded pages, which prevents us
from throwing other processes under the bus too soon.

• loader/cache/CachedResource.cpp:

(WebCore::CachedResource::deleteIfPossible):

• platform/SharedBuffer.cpp:

(WebCore::SharedBuffer::hintMemoryNotNeededSoon):

• platform/SharedBuffer.h:
• platform/cf/SharedBufferCF.cpp:

(WebCore::SharedBuffer::hintMemoryNotNeededSoon):

Source/WTF:

Add an API to OSAllocator for hinting to the OS that a range of memory
is not expected to be used anytime soon.

• wtf/OSAllocator.h:
• wtf/OSAllocatorPosix.cpp:

(WTF::OSAllocator::hintMemoryNotNeededSoon):

• wtf/OSAllocatorWin.cpp:

(WTF::OSAllocator::hintMemoryNotNeededSoon):

• wtf/Platform.h:

Location:

trunk/Source

Files:

• WTF/ChangeLog (modified) (1 diff)
• WTF/wtf/OSAllocator.h (modified) (1 diff)
• WTF/wtf/OSAllocatorPosix.cpp (modified) (1 diff)
• WTF/wtf/OSAllocatorWin.cpp (modified) (1 diff)
• WTF/wtf/Platform.h (modified) (1 diff)
• WebCore/ChangeLog (modified) (1 diff)
• WebCore/loader/cache/CachedResource.cpp (modified) (1 diff)
• WebCore/platform/SharedBuffer.cpp (modified) (1 diff)
• WebCore/platform/SharedBuffer.h (modified) (1 diff)
• WebCore/platform/cf/SharedBufferCF.cpp (modified) (2 diffs)

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2015-12-16  Andreas Kling  <akling@apple.com>
+
+        Give kernel VM some hints about non-live memory-cached resources.
+        <https://webkit.org/b/152362>
+
+        Reviewed by Geoffrey Garen.
+
+        Add an API to OSAllocator for hinting to the OS that a range of memory
+        is not expected to be used anytime soon.
+
+        * wtf/OSAllocator.h:
+        * wtf/OSAllocatorPosix.cpp:
+        (WTF::OSAllocator::hintMemoryNotNeededSoon):
+        * wtf/OSAllocatorWin.cpp:
+        (WTF::OSAllocator::hintMemoryNotNeededSoon):
+        * wtf/Platform.h:
+
 2015-12-16  Alex Christensen  <achristensen@webkit.org>
 

trunk/Source/WTF/wtf/OSAllocator.h

@@ -70 +70 @@
     template<typename T>
     static T* reallocateCommitted(T*, size_t oldSize, size_t newSize, Usage = UnknownUsage, bool writable = true, bool executable = false);
+
+    // Hint to the OS that an address range is not expected to be accessed anytime soon.
+    WTF_EXPORT_PRIVATE static void hintMemoryNotNeededSoon(void*, size_t);
 };
 

trunk/Source/WTF/wtf/OSAllocatorPosix.cpp

@@ -165 +165 @@
 }
 
+void OSAllocator::hintMemoryNotNeededSoon(void* address, size_t bytes)
+{
+#if HAVE(MADV_DONTNEED)
+    while (madvise(address, bytes, MADV_DONTNEED) == -1 && errno == EAGAIN) { }
+#else
+    UNUSED_PARAM(address);
+    UNUSED_PARAM(bytes);
+#endif
+}
+
 void OSAllocator::releaseDecommitted(void* address, size_t bytes)
 {

trunk/Source/WTF/wtf/OSAllocatorWin.cpp

@@ -94 +94 @@
 }
 
+void OSAllocator::hintMemoryNotNeededSoon(void*, size_t)
+{
+}
+
 } // namespace WTF
 

trunk/Source/WTF/wtf/Platform.h

@@ -631 +631 @@
 #define HAVE_MADV_FREE 1
 #define HAVE_MADV_FREE_REUSE 1
+#define HAVE_MADV_DONTNEED 1
 #define HAVE_MERGESORT 1
 #define HAVE_PTHREAD_SETNAME_NP 1

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-12-16  Andreas Kling  <akling@apple.com>
+
+        Give kernel VM some hints about non-live memory-cached resources.
+        <https://webkit.org/b/152362>
+
+        Reviewed by Geoffrey Garen.
+
+        When a file-backed CachedResource has no live clients left, and is only being kept alive
+        because it's cached in the MemoryCache, give the OS a hint that we probably won't need
+        that memory very soon.
+
+        Normally this doesn't do anything, but in case the system comes under memory pressure,
+        the kernel can prioritize eviction of such clean-but-unneeded pages, which prevents us
+        from throwing other processes under the bus too soon.
+
+        * loader/cache/CachedResource.cpp:
+        (WebCore::CachedResource::deleteIfPossible):
+        * platform/SharedBuffer.cpp:
+        (WebCore::SharedBuffer::hintMemoryNotNeededSoon):
+        * platform/SharedBuffer.h:
+        * platform/cf/SharedBufferCF.cpp:
+        (WebCore::SharedBuffer::hintMemoryNotNeededSoon):
+
 2015-12-16  Gyuyoung Kim  <gyuyoung.kim@webkit.org>
 

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

@@ -505 +505 @@
 bool CachedResource::deleteIfPossible()
 {
-    if (canDelete() && !inCache()) {
-        InspectorInstrumentation::willDestroyCachedResource(*this);
-        delete this;
-        return true;
+    if (canDelete()) {
+        if (!inCache()) {
+            InspectorInstrumentation::willDestroyCachedResource(*this);
+            delete this;
+            return true;
+        }
+        if (m_data)
+            m_data->hintMemoryNotNeededSoon();
     }
     return false;

trunk/Source/WebCore/platform/SharedBuffer.cpp

@@ -303 +303 @@
 }
 
+#if !USE(CF)
+void SharedBuffer::hintMemoryNotNeededSoon()
+{
+}
+#endif
+
 #if !USE(NETWORK_CFDATA_ARRAY_CALLBACK)
 

trunk/Source/WebCore/platform/SharedBuffer.h

@@ -127 +127 @@
     };
 
+    void hintMemoryNotNeededSoon();
+
 private:
     WEBCORE_EXPORT SharedBuffer();

trunk/Source/WebCore/platform/cf/SharedBufferCF.cpp

@@ -29 +29 @@
 #include "SharedBuffer.h"
 
+#include <wtf/OSAllocator.h>
 #include <wtf/cf/TypeCastsCF.h>
 
@@ -72 +73 @@
 {
     return CFDataGetLength(m_cfData.get());
+}
+
+void SharedBuffer::hintMemoryNotNeededSoon()
+{
+    if (!hasPlatformData())
+        return;
+    OSAllocator::hintMemoryNotNeededSoon(const_cast<char*>(platformData()), platformDataSize());
 }