[Beignet] [PATCH] Move the gpgpu struct from cl_command_queue to thread specific context

He Junyan junyan.he at inbox.com
Thu Nov 7 19:20:41 PST 2013


So can I understand like this:
TLS (Thread local storage) is a global section map to each thread's
space. Each thread keep one copy of this section's copy.
And thread_specific is in heap, using sync function to manage the
resource for each thread. 
?


On Fri, 2013-11-08 at 02:58 +0000, Zou, Nanhai wrote:
> TLS (Thread local storage) is useful for convert legacy thread unsafe program into thread-safe. 
> E.g. errno in glibc.
> 
> But for this case, I think explicitly separate the thread specific data is better. 
> Not only for thread safe, but also for later optimization. 
> This help us to collect all data that will be modified during NDRange.
> 
> Thanks
> Zou Nanhai
> 
> -----Original Message-----
> From: beignet-bounces at lists.freedesktop.org [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of Song, Ruiling
> Sent: Friday, November 08, 2013 10:38 AM
> To: Zhigang Gong; junyan.he at inbox.com
> Cc: Junyan He; beignet at lists.freedesktop.org
> Subject: Re: [Beignet] [PATCH] Move the gpgpu struct from cl_command_queue to thread specific context
> 
> I am really new to the keyword "__thread", and have a quick look at docs on the web:
> http://gcc.gnu.org/onlinedocs/gcc-3.3.1/gcc/Thread-Local.html#Thread-Local
> it says: "The __thread specifier may be applied to any global, file-scoped static, function-scoped static, or static data member of a class. It may not be applied to block-scoped automatic or non-static data member. "
> From my understanding, this is not proper for our case.
> 
> Thanks!
> Ruiling
> -----Original Message-----
> From: beignet-bounces at lists.freedesktop.org [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of Zhigang Gong
> Sent: Friday, November 08, 2013 8:29 AM
> To: junyan.he at inbox.com
> Cc: Junyan He; beignet at lists.freedesktop.org
> Subject: Re: [Beignet] [PATCH] Move the gpgpu struct from cl_command_queue to thread specific context
> 
> I agree with you that use thread data is better than locking.
> One comment, how about to use thread local storage to simplify this patch as below:
> 
> struct _cl_commonand_queue {
> ...
> __thread cl_gpgpu gpgpu;
> ...
> };
> 
> Then in the initialization stage, set it to NULL;
> 
> queue->gpgpu = NULL;
> 
> In the head of each functions which use queue->gpgpu, add the following
> code:
> 
> if (queue->gpgpu == NULL)
>   TRY_ALLOC_NO_ERR (queue->gpgpu, cl_gpgpu_new(ctx->drv));
> 
> Then we don't need to change any other code?
> 
> What's your opinion?
> 
> On Fri, Nov 08, 2013 at 12:58:00AM +0800, junyan.he at inbox.com wrote:
> > From: Junyan He <junyan.he at linux.intel.com>
> > 
> > We find some cases will use multi-threads to run on the same queue, 
> > executing the same kernel. This will cause the gpgpu struct which is 
> > very important for GPU context setting be destroyed because we do not 
> > implement any sync protect on it now.
> > Move the gpgpu struct into thread specific space will fix this problem 
> > because the lib_drm will do the GPU command serialization for us.
> > ---
> >  src/CMakeLists.txt          |    1 +
> >  src/cl_command_queue.c      |   27 +++++++++++-----
> >  src/cl_command_queue.h      |    9 +++++-
> >  src/cl_command_queue_gen7.c |    7 +++--
> >  src/cl_event.c              |    6 ++--
> >  src/cl_thread.c             |   72 +++++++++++++++++++++++++++++++++++++++++++
> >  src/cl_thread.h             |   34 ++++++++++++++++++++
> >  utests/CMakeLists.txt       |    2 +-
> >  8 files changed, 144 insertions(+), 14 deletions(-)  create mode
> > 100644 src/cl_thread.c  create mode 100644 src/cl_thread.h
> > 
> > diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt index 
> > 1e28c6c..59d330e 100644
> > --- a/src/CMakeLists.txt
> > +++ b/src/CMakeLists.txt
> > @@ -39,6 +39,7 @@ set(OPENCL_SRC
> >      cl_command_queue.c
> >      cl_command_queue.h
> >      cl_command_queue_gen7.c
> > +    cl_thread.c
> >      cl_driver.h
> >      cl_driver.cpp
> >      cl_driver_defs.c
> > diff --git a/src/cl_command_queue.c b/src/cl_command_queue.c index
> > 3f9d95c..3530976 100644
> > --- a/src/cl_command_queue.c
> > +++ b/src/cl_command_queue.c
> > @@ -24,6 +24,7 @@
> >  #include "cl_device_id.h"
> >  #include "cl_mem.h"
> >  #include "cl_utils.h"
> > +#include "cl_thread.h"
> >  #include "cl_alloc.h"
> >  #include "cl_driver.h"
> >  #include "cl_khr_icd.h"
> > @@ -43,7 +44,9 @@ cl_command_queue_new(cl_context ctx)
> >    queue->magic = CL_MAGIC_QUEUE_HEADER;
> >    queue->ref_n = 1;
> >    queue->ctx = ctx;
> > -  TRY_ALLOC_NO_ERR (queue->gpgpu, cl_gpgpu_new(ctx->drv));
> > +  if ((queue->thread_data = cl_thread_data_create()) == NULL) {
> > +    goto error;
> > +  }
> >  
> >    /* Append the command queue in the list */
> >    pthread_mutex_lock(&ctx->queue_lock);
> > @@ -84,9 +87,11 @@ cl_command_queue_delete(cl_command_queue queue)
> >      cl_mem_delete(queue->fulsim_out);
> >      queue->fulsim_out = NULL;
> >    }
> > +
> > +  cl_thread_data_destroy(queue->thread_data);
> > +  queue->thread_data = NULL;
> >    cl_mem_delete(queue->perf);
> >    cl_context_delete(queue->ctx);
> > -  cl_gpgpu_delete(queue->gpgpu);
> >    cl_free(queue->wait_events);
> >    queue->magic = CL_MAGIC_DEAD_HEADER; /* For safety */
> >    cl_free(queue);
> > @@ -119,13 +124,15 @@ LOCAL cl_int
> >  cl_command_queue_bind_image(cl_command_queue queue, cl_kernel k)  {
> >    uint32_t i;
> > +  GET_QUEUE_THREAD_GPGPU(queue);
> > +
> >    for (i = 0; i < k->image_sz; i++) {
> >      int id = k->images[i].arg_idx;
> >      struct _cl_mem_image *image;
> >      assert(gbe_kernel_get_arg_type(k->opaque, id) == GBE_ARG_IMAGE);
> >      image = cl_mem_image(k->args[id].mem);
> >      set_image_info(k->curbe, &k->images[i], image);
> > -    cl_gpgpu_bind_image(queue->gpgpu, k->images[i].idx, image->base.bo, image->offset,
> > +    cl_gpgpu_bind_image(gpgpu, k->images[i].idx, image->base.bo,
> > + image->offset,
> >                          image->intel_fmt, image->image_type,
> >                          image->w, image->h, image->depth,
> >                          image->row_pitch, image->tiling); @@ -136,6
> > +143,8 @@ cl_command_queue_bind_image(cl_command_queue queue,
> > cl_kernel k)  LOCAL cl_int
> > cl_command_queue_bind_surface(cl_command_queue queue, cl_kernel k)  {
> > +  GET_QUEUE_THREAD_GPGPU(queue);
> > +
> >    /* Bind all user buffers (given by clSetKernelArg) */
> >    uint32_t i;
> >    enum gbe_arg_type arg_type; /* kind of argument */ @@ -147,9 +156,9 
> > @@ cl_command_queue_bind_surface(cl_command_queue queue, cl_kernel k)
> >      offset = gbe_kernel_get_curbe_offset(k->opaque, GBE_CURBE_KERNEL_ARGUMENT, i);
> >      if (k->args[i].mem->type == CL_MEM_SUBBUFFER_TYPE) {
> >        struct _cl_mem_buffer* buffer = (struct _cl_mem_buffer*)k->args[i].mem;
> > -      cl_gpgpu_bind_buf(queue->gpgpu, k->args[i].mem->bo, offset, buffer->sub_offset, cc_llc_l3);
> > +      cl_gpgpu_bind_buf(gpgpu, k->args[i].mem->bo, offset,
> > + buffer->sub_offset, cc_llc_l3);
> >      } else {
> > -      cl_gpgpu_bind_buf(queue->gpgpu, k->args[i].mem->bo, offset, 0, cc_llc_l3);
> > +      cl_gpgpu_bind_buf(gpgpu, k->args[i].mem->bo, offset, 0, 
> > + cc_llc_l3);
> >      }
> >    }
> >  
> > @@ -407,14 +416,18 @@ error:
> >  LOCAL cl_int
> >  cl_command_queue_flush(cl_command_queue queue)  {
> > -  cl_gpgpu_flush(queue->gpgpu);
> > +  GET_QUEUE_THREAD_GPGPU(queue);
> > +
> > +  cl_gpgpu_flush(gpgpu);
> >    return CL_SUCCESS;
> >  }
> >  
> >  LOCAL cl_int
> >  cl_command_queue_finish(cl_command_queue queue)  {
> > -  cl_gpgpu_sync(queue->gpgpu);
> > +  GET_QUEUE_THREAD_GPGPU(queue);
> > +
> > +  cl_gpgpu_sync(gpgpu);
> >    return CL_SUCCESS;
> >  }
> >  
> > diff --git a/src/cl_command_queue.h b/src/cl_command_queue.h index 
> > 9396fd7..40c272c 100644
> > --- a/src/cl_command_queue.h
> > +++ b/src/cl_command_queue.h
> > @@ -22,6 +22,7 @@
> >  
> >  #include "cl_internals.h"
> >  #include "cl_driver.h"
> > +#include "cl_thread.h"
> >  #include "CL/cl.h"
> >  #include <stdint.h>
> >  
> > @@ -40,11 +41,17 @@ struct _cl_command_queue {
> >    cl_event  last_event;                /* The last event in the queue, for enqueue mark used */
> >    cl_command_queue_properties  props;  /* Queue properties */
> >    cl_command_queue prev, next;         /* We chain the command queues together */
> > -  cl_gpgpu gpgpu;                      /* Setup all GEN commands */
> > +  void *thread_data;                   /* Used to store thread context data */
> >    cl_mem perf;                         /* Where to put the perf counters */
> >    cl_mem fulsim_out;                   /* Fulsim will output this buffer */
> >  };
> >  
> > +/* The macro to get the thread specified gpgpu struct. */ #define
> > +GET_QUEUE_THREAD_GPGPU(queue) \
> > +	cl_gpgpu gpgpu = queue ? cl_get_thread_gpgpu(queue) : NULL;  \
> > +	if (queue) \
> > +	  assert(gpgpu);
> > +
> >  /* Allocate and initialize a new command queue. Also insert it in the list of
> >   * command queue in the associated context
> >   */
> > diff --git a/src/cl_command_queue_gen7.c b/src/cl_command_queue_gen7.c 
> > index 65f8e17..fb7a8a3 100644
> > --- a/src/cl_command_queue_gen7.c
> > +++ b/src/cl_command_queue_gen7.c
> > @@ -99,6 +99,7 @@ static void
> >  cl_upload_constant_buffer(cl_command_queue queue, cl_kernel ker)  {
> >    /* calculate constant buffer size */
> > +  GET_QUEUE_THREAD_GPGPU(queue);
> >    int32_t arg;
> >    size_t offset;
> >    gbe_program prog = ker->program->opaque; @@ -115,7 +116,7 @@ 
> > cl_upload_constant_buffer(cl_command_queue queue, cl_kernel ker)
> >    if(global_const_size == 0 && constant_buf_size == 0)
> >       return;
> >  
> > -  cl_buffer bo = cl_gpgpu_alloc_constant_buffer(queue->gpgpu,
> > constant_buf_size + global_const_size + 4);
> > +  cl_buffer bo = cl_gpgpu_alloc_constant_buffer(gpgpu,
> > + constant_buf_size + global_const_size + 4);
> >    cl_buffer_map(bo, 1);
> >    char * cst_addr = cl_buffer_get_virtual(bo);
> >    offset = 0;
> > @@ -256,8 +257,8 @@ cl_command_queue_ND_range_gen7(cl_command_queue queue,
> >                                 const size_t *global_wk_sz,
> >                                 const size_t *local_wk_sz)  {
> > +  GET_QUEUE_THREAD_GPGPU(queue);
> >    cl_context ctx = queue->ctx;
> > -  cl_gpgpu gpgpu = queue->gpgpu;
> >    char *final_curbe = NULL;  /* Includes them and one sub-buffer per group */
> >    cl_gpgpu_kernel kernel;
> >    const uint32_t simd_sz = cl_kernel_get_simd_width(ker); @@ -297,7
> > +298,7 @@ cl_command_queue_ND_range_gen7(cl_command_queue queue,
> >    /* Bind user images */
> >    cl_command_queue_bind_image(queue, ker);
> >    /* Bind all samplers */
> > -  cl_gpgpu_bind_sampler(queue->gpgpu, ker->samplers,
> > ker->sampler_sz);
> > +  cl_gpgpu_bind_sampler(gpgpu, ker->samplers, ker->sampler_sz);
> >  
> >    cl_setup_scratch(gpgpu, ker);
> >    /* Bind a stack if needed */
> > diff --git a/src/cl_event.c b/src/cl_event.c index 1dc02ae..028dfb6
> > 100644
> > --- a/src/cl_event.c
> > +++ b/src/cl_event.c
> > @@ -48,6 +48,7 @@ cl_event_is_gpu_command_type(cl_command_type type) 
> > cl_event cl_event_new(cl_context ctx, cl_command_queue queue, 
> > cl_command_type type, cl_bool emplict)  {
> >    cl_event event = NULL;
> > +  GET_QUEUE_THREAD_GPGPU(queue);
> >  
> >    /* Allocate and inialize the structure itself */
> >    TRY_ALLOC_NO_ERR (event, CALLOC(struct _cl_event)); @@ -75,7 +76,7 
> > @@ cl_event cl_event_new(cl_context ctx, cl_command_queue queue, cl_command_type ty
> >    else {
> >      event->status = CL_QUEUED;
> >      if(cl_event_is_gpu_command_type(event->type))
> > -      event->gpgpu_event = cl_gpgpu_event_new(queue->gpgpu);
> > +      event->gpgpu_event = cl_gpgpu_event_new(gpgpu);
> >    }
> >    cl_event_add_ref(event);       //dec when complete
> >    event->user_cb = NULL;
> > @@ -257,6 +258,7 @@ void cl_event_new_enqueue_callback(cl_event event,
> >    user_event *user_events, *u_ev;
> >    cl_command_queue queue = event->queue;
> >    cl_int i;
> > +  GET_QUEUE_THREAD_GPGPU(data->queue);
> >  
> >    /* Allocate and inialize the structure itself */
> >    TRY_ALLOC_NO_ERR (cb, CALLOC(enqueue_callback)); @@ -336,7 +338,7 
> > @@ void cl_event_new_enqueue_callback(cl_event event,
> >      }
> >    }
> >    if(data->queue != NULL && event->gpgpu_event != NULL) {
> > -    cl_gpgpu_event_pending(data->queue->gpgpu, event->gpgpu_event);
> > +    cl_gpgpu_event_pending(gpgpu, event->gpgpu_event);
> >      data->ptr = (void *)event->gpgpu_event;
> >    }
> >    cb->data = *data;
> > diff --git a/src/cl_thread.c b/src/cl_thread.c new file mode 100644 
> > index 0000000..fbad5c5
> > --- /dev/null
> > +++ b/src/cl_thread.c
> > @@ -0,0 +1,72 @@
> > +/*
> > + * Copyright (c) 2012 Intel Corporation
> > + *
> > + * This library is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2 of the License, or (at your option) any later version.
> > + *
> > + * This library is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with this library. If not, see <http://www.gnu.org/licenses/>.
> > + *
> > + */
> > +
> > +#include "cl_thread.h"
> > +#include "cl_alloc.h"
> > +#include "cl_utils.h"
> > +
> > +cl_gpgpu cl_get_thread_gpgpu(cl_command_queue queue) {
> > +  pthread_key_t* key = queue->thread_data;
> > +  cl_gpgpu gpgpu = pthread_getspecific(*key);
> > +
> > +  if (!gpgpu) {
> > +    TRY_ALLOC_NO_ERR (gpgpu, cl_gpgpu_new(queue->ctx->drv));  }
> > +
> > +  if (pthread_setspecific(*key, gpgpu)) {
> > +    cl_gpgpu_delete(gpgpu);
> > +    goto error;
> > +  }
> > +
> > +exit:
> > +  return gpgpu;
> > +error:
> > +  pthread_setspecific(*key, NULL);
> > +  goto exit;
> > +}
> > +
> > +static void thread_data_destructor(void *data) {
> > +  cl_gpgpu gpgpu = (cl_gpgpu)data;
> > +  cl_gpgpu_delete(gpgpu);
> > +}
> > +
> > +/* Create the thread specific data. */
> > +void* cl_thread_data_create(void)
> > +{
> > +  int rc = 0;
> > +
> > +  pthread_key_t *thread_specific_key = CALLOC(pthread_key_t);  if 
> > + (thread_specific_key == NULL)
> > +    return NULL;
> > +
> > +  rc = pthread_key_create(thread_specific_key,
> > + thread_data_destructor);
> > +
> > +  if (rc != 0)
> > +    return NULL;
> > +
> > +  return thread_specific_key;
> > +}
> > +
> > +/* The destructor for clean the thread specific data. */ void 
> > +cl_thread_data_destroy(void * data) {
> > +  pthread_key_t *thread_specific_key = (pthread_key_t *)data;
> > +  pthread_key_delete(*thread_specific_key);
> > +  cl_free(thread_specific_key);
> > +}
> > diff --git a/src/cl_thread.h b/src/cl_thread.h new file mode 100644 
> > index 0000000..65f1bcf
> > --- /dev/null
> > +++ b/src/cl_thread.h
> > @@ -0,0 +1,34 @@
> > +/*
> > + * Copyright (c) 2012 Intel Corporation
> > + *
> > + * This library is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2 of the License, or (at your option) any later version.
> > + *
> > + * This library is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with this library. If not, see <http://www.gnu.org/licenses/>.
> > + *
> > + */
> > +
> > +#ifndef __CL_THREAD_H__
> > +#define __CL_THREAD_H__
> > +
> > +#include <pthread.h>
> > +#include "cl_internals.h"
> > +#include "cl_command_queue.h"
> > +
> > +/* Create the thread specific data. */
> > +void* cl_thread_data_create(void);
> > +
> > +/* The destructor for clean the thread specific data. */ void 
> > +cl_thread_data_destroy(void * data);
> > +
> > +/* Used to get the gpgpu struct of each thread. */ cl_gpgpu 
> > +cl_get_thread_gpgpu(cl_command_queue queue); #endif /* 
> > +__CL_THREAD_H__ */
> > diff --git a/utests/CMakeLists.txt b/utests/CMakeLists.txt index
> > c87cba8..5e0bc19 100644
> > --- a/utests/CMakeLists.txt
> > +++ b/utests/CMakeLists.txt
> > @@ -53,7 +53,7 @@ set (utests_sources
> >    compiler_if_else.cpp
> >    compiler_integer_division.cpp
> >    compiler_integer_remainder.cpp
> > -	compiler_insert_vector.cpp
> > +  compiler_insert_vector.cpp
> >    compiler_lower_return0.cpp
> >    compiler_lower_return1.cpp
> >    compiler_lower_return2.cpp
> > --
> > 1.7.9.5
> > 
> > 
> > 
> > _______________________________________________
> > Beignet mailing list
> > Beignet at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/beignet
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