Changeset 215220 in webkit

Timestamp:

Apr 11, 2017 1:27:28 AM (7 years ago)

Author:

zandobersek@gmail.com

Message:

REGRESSION(r213645): It made JSC tests super slow and timeout on AArch64 Linux
​https://bugs.webkit.org/show_bug.cgi?id=169510

Reviewed by Saam Barati.

Add the volatile qualifiers for ASM statements that set up ldxr and stxr
instruction calls when HAVE(LL_SC) is enabled for aarch64 platforms.

This avoids indefinite execution when running GCC-compiled JSC on Linux.
Specific bug or expected behavior that differs from Clang wasn't determined.

HAVE(LL_SC) is re-enabled on non-Darwin aarch64 platforms.

• wtf/Atomics.h:
• wtf/Platform.h:

Location:

trunk/Source/WTF

Files:

• ChangeLog (modified) (1 diff)
• wtf/Atomics.h (modified) (2 diffs)
• wtf/Platform.h (modified) (1 diff)

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2017-04-11  Zan Dobersek  <zdobersek@igalia.com>
+
+        REGRESSION(r213645): It made JSC tests super slow and timeout on AArch64 Linux
+        https://bugs.webkit.org/show_bug.cgi?id=169510
+
+        Reviewed by Saam Barati.
+
+        Add the `volatile` qualifiers for ASM statements that set up ldxr and stxr
+        instruction calls when HAVE(LL_SC) is enabled for aarch64 platforms.
+
+        This avoids indefinite execution when running GCC-compiled JSC on Linux.
+        Specific bug or expected behavior that differs from Clang wasn't determined.
+
+        HAVE(LL_SC) is re-enabled on non-Darwin aarch64 platforms.
+
+        * wtf/Atomics.h:
+        * wtf/Platform.h:
+
 2017-04-10  Thorsten Glaser  <tg@mirbsd.de>
 

trunk/Source/WTF/wtf/Atomics.h

@@ -191 +191 @@
                 : "memory"); \
         } else { \
-            asm ( \
+            asm volatile ( \
                 "ldxr" suffix " %" modifier "0, [%1]" \
                 : "=r"(result) \
@@ -211 +211 @@
                 : "memory"); \
         } else { \
-            asm ( \
+            asm volatile ( \
                 "stxr" suffix " %w0, %" modifier "1, [%2]" \
                 : "=&r"(result) \

trunk/Source/WTF/wtf/Platform.h

@@ -758 +758 @@
 #endif
 
-/* FIXME: Enable it on Linux once https://bugs.webkit.org/show_bug.cgi?id=169510 is fixed. */
-#if CPU(ARM64) && OS(DARWIN)
+#if CPU(ARM64)
 #define HAVE_LL_SC 1
 #endif // CPU(ARM64) && OS(DARWIN)