[Mesa-dev] [PATCH 11/11] ac/radv: using tls to store llvm related info and speed up compiles (v3)
Marek Olšák
maraeo at gmail.com
Sat Jun 30 04:11:44 UTC 2018
I wonder if we can somehow make the TLS magic apply to RADV only.
Radeonsi can do it without TLS. Then, the RADV-specific TLS code can be
moved to RADV, and other code (if any) can be shared.
It doesn't make much sense to do the TLS initialization in
ac_llvm_compiler_init. It could be done in compile_to_memory_buffer
and the fail path there could be removed.
The call to LLVMTargetMachineEmitToMemoryBuffer can be removed.
There is no use for it. Things like if(radv) and if(radeonsi) don't
look good in the common code even if you don't write it exactly like
that.
Marek
On Tue, Jun 26, 2018 at 11:58 PM, Dave Airlie <airlied at gmail.com> wrote:
> From: Dave Airlie <airlied at redhat.com>
>
> I'd like to encourage people to test this to see if it helps (like
> does it make app startup better or less hitching in dxvk).
>
> The basic idea is to store a bunch of LLVM related data structs
> in thread local storage so we can avoid reiniting them every time
> we compile a shader. Since we know llvm objects aren't thread safe
> it has to be stored using TLS to avoid any collisions.
>
> This should remove all the fixed overheads setup costs of creating
> the pass manager each time.
>
> This takes a demo app time to compile the radv meta shaders on nocache
> and exit from 1.7s to 1s.
>
> TODO: this doesn't work for radeonsi yet, but I'm not sure how TLS
> works if you have radeonsi and radv loaded at the same time, if
> they'll magically try and use the same tls stuff, in which case
> this might explode all over the place.
>
> v2: fix llvm6 build, inline emit function, handle multiple targets
> in one thread
> v3: rebase and port onto new structure
> ---
> src/amd/common/ac_llvm_helper.cpp | 120 ++++++++++++++++++++++++++++--
> src/amd/common/ac_llvm_util.c | 10 +--
> src/amd/common/ac_llvm_util.h | 9 +++
> src/amd/vulkan/radv_debug.h | 1 +
> src/amd/vulkan/radv_device.c | 1 +
> src/amd/vulkan/radv_shader.c | 2 +
> 6 files changed, 132 insertions(+), 11 deletions(-)
>
> diff --git a/src/amd/common/ac_llvm_helper.cpp b/src/amd/common/ac_llvm_helper.cpp
> index 27403dbe085..f1f1399b3fb 100644
> --- a/src/amd/common/ac_llvm_helper.cpp
> +++ b/src/amd/common/ac_llvm_helper.cpp
> @@ -31,12 +31,21 @@
>
> #include "ac_llvm_util.h"
> #include <llvm-c/Core.h>
> -#include <llvm/Target/TargetOptions.h>
> -#include <llvm/ExecutionEngine/ExecutionEngine.h>
> -#include <llvm/IR/Attributes.h>
> -#include <llvm/IR/CallSite.h>
> +#include <llvm/Target/TargetMachine.h>
> #include <llvm/IR/IRBuilder.h>
> #include <llvm/Analysis/TargetLibraryInfo.h>
> +#include <llvm/IR/LegacyPassManager.h>
> +
> +#include <llvm-c/Transforms/IPO.h>
> +#include <llvm-c/Transforms/Scalar.h>
> +#if HAVE_LLVM >= 0x0700
> +#include <llvm-c/Transforms/Utils.h>
> +#endif
> +
> +#if HAVE_LLVM < 0x0700
> +#include "llvm/Support/raw_ostream.h"
> +#endif
> +#include <list>
>
> void ac_add_attr_dereferenceable(LLVMValueRef val, uint64_t bytes)
> {
> @@ -101,11 +110,110 @@ ac_dispose_target_library_info(LLVMTargetLibraryInfoRef library_info)
> delete reinterpret_cast<llvm::TargetLibraryInfoImpl *>(library_info);
> }
>
> +class ac_llvm_per_thread_info {
> +public:
> + ac_llvm_per_thread_info(enum radeon_family arg_family,
> + enum ac_target_machine_options arg_tm_options)
> + : family(arg_family), tm_options(arg_tm_options),
> + OStream(CodeString) {}
> + ~ac_llvm_per_thread_info() {
> + ac_llvm_compiler_dispose_internal(&llvm_info);
> + }
> +
> + struct ac_llvm_compiler_info llvm_info;
> + enum radeon_family family;
> + enum ac_target_machine_options tm_options;
> + llvm::SmallString<0> CodeString;
> + llvm::raw_svector_ostream OStream;
> + llvm::legacy::PassManager pass;
> +};
> +
> +/* we have to store a linked list per thread due to the possiblity of multiple gpus being required */
> +static thread_local std::list<ac_llvm_per_thread_info> ac_llvm_per_thread_list;
> +
> bool ac_compile_to_memory_buffer(struct ac_llvm_compiler_info *info,
> LLVMModuleRef M,
> char **ErrorMessage,
> LLVMMemoryBufferRef *OutMemBuf)
> {
> - return LLVMTargetMachineEmitToMemoryBuffer(info->tm, M, LLVMObjectFile,
> - ErrorMessage, OutMemBuf);
> + ac_llvm_per_thread_info *thread_info = nullptr;
> + if (info->thread_stored) {
> + for (auto &I : ac_llvm_per_thread_list) {
> + if (I.llvm_info.tm == info->tm) {
> + thread_info = &I;
> + break;
> + }
> + }
> +
> + if (!thread_info) {
> + assert(0);
> + return false;
> + }
> + } else {
> + return LLVMTargetMachineEmitToMemoryBuffer(info->tm, M, LLVMObjectFile,
> + ErrorMessage, OutMemBuf);
> + }
> +
> + llvm::TargetMachine *TM = reinterpret_cast<llvm::TargetMachine*>(thread_info->llvm_info.tm);
> + llvm::Module *Mod = llvm::unwrap(M);
> + llvm::StringRef Data;
> +
> + Mod->setDataLayout(TM->createDataLayout());
> +
> + thread_info->pass.run(*Mod);
> +
> + Data = thread_info->OStream.str();
> + *OutMemBuf = LLVMCreateMemoryBufferWithMemoryRangeCopy(Data.data(), Data.size(), "");
> + thread_info->CodeString = "";
> + return false;
> +}
> +
> +bool ac_llvm_compiler_init(struct ac_llvm_compiler_info *info,
> + bool add_target_library_info,
> + enum radeon_family family,
> + enum ac_target_machine_options tm_options)
> +{
> + if (tm_options & AC_TM_THREAD_LLVM) {
> + for (auto &I : ac_llvm_per_thread_list) {
> + if (I.family == family &&
> + I.tm_options == tm_options) {
> + *info = I.llvm_info;
> + return true;
> + }
> + }
> +
> + ac_llvm_per_thread_list.emplace_back(family, tm_options);
> + ac_llvm_per_thread_info &tinfo = ac_llvm_per_thread_list.back();
> + if (!ac_llvm_compiler_init_internal(&tinfo.llvm_info,
> + true,
> + family,
> + tm_options))
> + return false;
> +
> + tinfo.llvm_info.thread_stored = true;
> + *info = tinfo.llvm_info;
> +
> + llvm::TargetMachine *TM = reinterpret_cast<llvm::TargetMachine*>(tinfo.llvm_info.tm);
> + if (TM->addPassesToEmitFile(tinfo.pass, tinfo.OStream,
> +#if HAVE_LLVM >= 0x0700
> + nullptr,
> +#endif
> + llvm::TargetMachine::CGFT_ObjectFile)) {
> + assert(0);
> + return false;
> + }
> + } else {
> + if (!ac_llvm_compiler_init_internal(info,
> + add_target_library_info,
> + family,
> + tm_options))
> + return false;
> + }
> + return true;
> +}
> +
> +void ac_llvm_compiler_dispose(struct ac_llvm_compiler_info *info)
> +{
> + if (!info->thread_stored)
> + ac_llvm_compiler_dispose_internal(info);
> }
> diff --git a/src/amd/common/ac_llvm_util.c b/src/amd/common/ac_llvm_util.c
> index 7f8c5746b37..d8ec4ee0092 100644
> --- a/src/amd/common/ac_llvm_util.c
> +++ b/src/amd/common/ac_llvm_util.c
> @@ -188,10 +188,10 @@ static LLVMPassManagerRef ac_init_passmgr(LLVMTargetLibraryInfoRef target_librar
> return passmgr;
> }
>
> -bool ac_llvm_compiler_init(struct ac_llvm_compiler_info *info,
> - bool add_target_library_info,
> - enum radeon_family family,
> - enum ac_target_machine_options tm_options)
> +bool ac_llvm_compiler_init_internal(struct ac_llvm_compiler_info *info,
> + bool add_target_library_info,
> + enum radeon_family family,
> + enum ac_target_machine_options tm_options)
> {
> memset(info, 0, sizeof(*info));
> info->tm = ac_create_target_machine(family, tm_options, &info->triple);
> @@ -223,7 +223,7 @@ fail:
> return false;
> }
>
> -void ac_llvm_compiler_dispose(struct ac_llvm_compiler_info *info)
> +void ac_llvm_compiler_dispose_internal(struct ac_llvm_compiler_info *info)
> {
> if (info->data_layout)
> LLVMDisposeMessage((char*)info->data_layout);
> diff --git a/src/amd/common/ac_llvm_util.h b/src/amd/common/ac_llvm_util.h
> index 1ba972dab87..c579e6a9ec3 100644
> --- a/src/amd/common/ac_llvm_util.h
> +++ b/src/amd/common/ac_llvm_util.h
> @@ -60,6 +60,7 @@ enum ac_target_machine_options {
> AC_TM_FORCE_DISABLE_XNACK = (1 << 3),
> AC_TM_PROMOTE_ALLOCA_TO_SCRATCH = (1 << 4),
> AC_TM_CHECK_IR = (1 << 5),
> + AC_TM_THREAD_LLVM = (1 << 6),
> };
>
> enum ac_float_mode {
> @@ -74,6 +75,7 @@ struct ac_llvm_compiler_info {
> LLVMTargetLibraryInfoRef target_library_info;
> const char *triple;
> const char *data_layout;
> + bool thread_stored;
> };
>
> const char *ac_get_llvm_processor_name(enum radeon_family family);
> @@ -114,6 +116,12 @@ ac_get_store_intr_attribs(bool writeonly_memory)
> unsigned
> ac_count_scratch_private_memory(LLVMValueRef function);
>
> +bool ac_llvm_compiler_init_internal(struct ac_llvm_compiler_info *info,
> + bool add_target_library_info, /* crash workaround */
> + enum radeon_family family,
> + enum ac_target_machine_options tm_options);
> +void ac_llvm_compiler_dispose_internal(struct ac_llvm_compiler_info *info);
> +
> bool ac_llvm_compiler_init(struct ac_llvm_compiler_info *info,
> bool add_target_library_info, /* crash workaround */
> enum radeon_family family,
> @@ -127,6 +135,7 @@ bool ac_compile_to_memory_buffer(struct ac_llvm_compiler_info *info,
> LLVMModuleRef M,
> char **ErrorMessage,
> LLVMMemoryBufferRef *OutMemBuf);
> +
> #ifdef __cplusplus
> }
> #endif
> diff --git a/src/amd/vulkan/radv_debug.h b/src/amd/vulkan/radv_debug.h
> index f1b0dc26a63..9fe4c3b7404 100644
> --- a/src/amd/vulkan/radv_debug.h
> +++ b/src/amd/vulkan/radv_debug.h
> @@ -49,6 +49,7 @@ enum {
> RADV_DEBUG_ERRORS = 0x80000,
> RADV_DEBUG_STARTUP = 0x100000,
> RADV_DEBUG_CHECKIR = 0x200000,
> + RADV_DEBUG_NOTHREADLLVM = 0x400000,
> };
>
> enum {
> diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
> index ad3465f594e..73c48cef1f0 100644
> --- a/src/amd/vulkan/radv_device.c
> +++ b/src/amd/vulkan/radv_device.c
> @@ -436,6 +436,7 @@ static const struct debug_control radv_debug_options[] = {
> {"errors", RADV_DEBUG_ERRORS},
> {"startup", RADV_DEBUG_STARTUP},
> {"checkir", RADV_DEBUG_CHECKIR},
> + {"nothreadllvm", RADV_DEBUG_NOTHREADLLVM},
> {NULL, 0}
> };
>
> diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c
> index 3bbb7867640..f7033aff771 100644
> --- a/src/amd/vulkan/radv_shader.c
> +++ b/src/amd/vulkan/radv_shader.c
> @@ -547,6 +547,8 @@ shader_variant_create(struct radv_device *device,
> tm_options |= AC_TM_SISCHED;
> if (options->check_ir)
> tm_options |= AC_TM_CHECK_IR;
> + if (!(device->instance->debug_flags & RADV_DEBUG_NOTHREADLLVM))
> + tm_options |= AC_TM_THREAD_LLVM;
>
> radv_init_llvm_once();
>
> --
> 2.17.1
>
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