Hi,
This change adds application global locking around compiling an r600 llvm
shader. This fixes a race condition/crash that I observe when shaders are
concurrently compiled from different contexts in different threads.
The fix is crude as it just guards the whole compile with a global mutex, but
up to now I did not have enough time to understand the real reason that must
be somewhere in the way r600g initializes the llvm backend. And since we have
a pending public release we will better have a curde fix than a known bug.
Better solutions welcome!
I will post a piglit test in the next minutes that exercises this problem with
a high probability at least here on my test machine.
Please review
Mathias
>From 6501efdb1ef9f52b584a709c4d24e095b67fc91d Mon Sep 17 00:00:00 2001
Message-Id: <6501efdb1ef9f52b584a709c4d24e095b67fc91d.1345008604.git.mathias.froehl...@gmx.net>
From: =?UTF-8?q?Mathias=20Fr=C3=B6hlich?= <mathias.froehl...@gmx.net>
Date: Fri, 10 Aug 2012 22:20:06 +0200
Subject: [PATCH] radeon_llvm: Introduce global lock on llvm.
No clue what is really racing here, but this fixes
sporadic crashes running osgviewer with multiple
windows together with the r600 llvm shader compiler.
Signed-off-by: Mathias Froehlich <mathias.froehl...@web.de>
---
src/gallium/drivers/radeon/radeon_llvm.h | 10 ++++++++
src/gallium/drivers/radeon/radeon_llvm_emit.cpp | 14 +++++++++--
.../drivers/radeon/radeon_setup_tgsi_llvm.c | 28 ++++++++++++++++++++++
3 files changed, 50 insertions(+), 2 deletions(-)
diff --git a/src/gallium/drivers/radeon/radeon_llvm.h b/src/gallium/drivers/radeon/radeon_llvm.h
index 7a32bb0..d1b6d17 100644
--- a/src/gallium/drivers/radeon/radeon_llvm.h
+++ b/src/gallium/drivers/radeon/radeon_llvm.h
@@ -142,6 +142,16 @@ static inline LLVMValueRef bitcast(
return value;
}
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void radeon_llvm_lock(void);
+void radeon_llvm_unlock(void);
+
+#ifdef __cplusplus
+}
+#endif
void radeon_llvm_context_init(struct radeon_llvm_context * ctx);
diff --git a/src/gallium/drivers/radeon/radeon_llvm_emit.cpp b/src/gallium/drivers/radeon/radeon_llvm_emit.cpp
index 89130b3..39b4640 100644
--- a/src/gallium/drivers/radeon/radeon_llvm_emit.cpp
+++ b/src/gallium/drivers/radeon/radeon_llvm_emit.cpp
@@ -48,15 +48,19 @@
using namespace llvm;
-#ifndef EXTERNAL_LLVM
extern "C" {
+#ifndef EXTERNAL_LLVM
void LLVMInitializeAMDGPUTargetMC(void);
void LLVMInitializeAMDGPUTarget(void);
void LLVMInitializeAMDGPUTargetInfo(void);
-}
#endif
+void radeon_llvm_lock();
+void radeon_llvm_unlock();
+
+}
+
/**
* Compile an LLVM module to machine code.
*
@@ -68,6 +72,8 @@ radeon_llvm_compile(LLVMModuleRef M, unsigned char ** bytes,
unsigned * byte_count, const char * gpu_family,
unsigned dump) {
+ radeon_llvm_lock();
+
Triple AMDGPUTriple(sys::getDefaultTargetTriple());
#ifdef EXTERNAL_LLVM
@@ -82,6 +88,7 @@ radeon_llvm_compile(LLVMModuleRef M, unsigned char ** bytes,
std::string err;
const Target * AMDGPUTarget = TargetRegistry::lookupTarget("r600", err);
if(!AMDGPUTarget) {
+ radeon_llvm_unlock();
fprintf(stderr, "Can't find target: %s\n", err.c_str());
return 1;
}
@@ -119,6 +126,7 @@ radeon_llvm_compile(LLVMModuleRef M, unsigned char ** bytes,
/* Optional extra paramater true / false to disable verify */
if (AMDGPUTargetMachine.addPassesToEmitFile(PM, out, TargetMachine::CGFT_AssemblyFile,
true)){
+ radeon_llvm_unlock();
fprintf(stderr, "AddingPasses failed.\n");
return 1;
}
@@ -131,5 +139,7 @@ radeon_llvm_compile(LLVMModuleRef M, unsigned char ** bytes,
memcpy(*bytes, data.c_str(), data.length() * sizeof(unsigned char));
*byte_count = data.length();
+ radeon_llvm_unlock();
+
return 0;
}
diff --git a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
index 641d277..95dd419 100644
--- a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
+++ b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
@@ -36,10 +36,26 @@
#include "util/u_math.h"
#include "util/u_memory.h"
#include "util/u_debug.h"
+#include "os/os_thread.h"
#include <llvm-c/Core.h>
#include <llvm-c/Transforms/Scalar.h>
+/** llvm with its magnitudes of global variables and factories
+ * appears not to be thread safe. Until then, we sadly need a mutex.
+ */
+pipe_static_mutex(llvm_mutex);
+
+void radeon_llvm_lock()
+{
+ pipe_mutex_lock(llvm_mutex);
+}
+
+void radeon_llvm_unlock()
+{
+ pipe_mutex_unlock(llvm_mutex);
+}
+
static struct radeon_llvm_loop * get_current_loop(struct radeon_llvm_context * ctx)
{
return ctx->loop_depth > 0 ? ctx->loop + (ctx->loop_depth - 1) : NULL;
@@ -989,6 +1005,8 @@ void radeon_llvm_context_init(struct radeon_llvm_context * ctx)
LLVMTypeRef main_fn_type;
LLVMBasicBlockRef main_fn_body;
+ radeon_llvm_lock();
+
/* Initialize the gallivm object:
* We are only using the module, context, and builder fields of this struct.
* This should be enough for us to be able to pass our gallivm struct to the
@@ -1166,11 +1184,16 @@ void radeon_llvm_context_init(struct radeon_llvm_context * ctx)
bld_base->rsq_action.emit = build_tgsi_intrinsic_nomem;
bld_base->rsq_action.intr_name = "llvm.AMDGPU.rsq";
+
+ radeon_llvm_unlock();
}
void radeon_llvm_finalize_module(struct radeon_llvm_context * ctx)
{
struct gallivm_state * gallivm = ctx->soa.bld_base.base.gallivm;
+
+ radeon_llvm_lock();
+
/* End the main function with Return*/
LLVMBuildRetVoid(gallivm->builder);
@@ -1191,10 +1214,15 @@ void radeon_llvm_finalize_module(struct radeon_llvm_context * ctx)
LLVMDisposeBuilder(gallivm->builder);
LLVMDisposePassManager(gallivm->passmgr);
+ radeon_llvm_unlock();
}
void radeon_llvm_dispose(struct radeon_llvm_context * ctx)
{
+ radeon_llvm_lock();
+
LLVMDisposeModule(ctx->soa.bld_base.base.gallivm->module);
LLVMContextDispose(ctx->soa.bld_base.base.gallivm->context);
+
+ radeon_llvm_unlock();
}
--
1.7.11.2
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