<div dir="ltr"><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jan 18, 2019 at 6:08 PM Bas Nieuwenhuizen <<a href="mailto:bas@basnieuwenhuizen.nl">bas@basnieuwenhuizen.nl</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Fri, Jan 18, 2019 at 5:44 PM Marek Olšák <<a href="mailto:maraeo@gmail.com" target="_blank">maraeo@gmail.com</a>> wrote: > > From: Marek Olšák <<a href="mailto:marek.olsak@amd.com" target="_blank">marek.olsak@amd.com</a>> > > --- > src/gallium/auxiliary/Makefile.sources | 1 + > src/gallium/auxiliary/meson.build | 1 + > src/gallium/auxiliary/util/u_cpu_suballoc.h | 90 +++++++++++++++++++++ > 3 files changed, 92 insertions(+) > create mode 100644 src/gallium/auxiliary/util/u_cpu_suballoc.h > > diff --git a/src/gallium/auxiliary/Makefile.sources b/src/gallium/auxiliary/Makefile.sources > index 50e88088ff8..b26415858f6 100644 > --- a/src/gallium/auxiliary/Makefile.sources > +++ b/src/gallium/auxiliary/Makefile.sources > @@ -211,20 +211,21 @@ C_SOURCES := \ > util/u_bitmask.c \ > util/u_bitmask.h \ > util/u_blend.h \ > util/u_blit.c \ > util/u_blit.h \ > util/u_blitter.c \ > util/u_blitter.h \ > util/u_box.h \ > util/u_cache.c \ > util/u_cache.h \ > + util/u_cpu_suballoc.h \ > util/u_debug_gallium.h \ > util/u_debug_gallium.c \ > util/u_debug_describe.c \ > util/u_debug_describe.h \ > util/u_debug_flush.c \ > util/u_debug_flush.h \ > util/u_debug_image.c \ > util/u_debug_image.h \ > util/u_debug_memory.c \ > util/u_debug_refcnt.c \ > diff --git a/src/gallium/auxiliary/meson.build b/src/gallium/auxiliary/meson.build > index 57f7e69050f..7e1e4732421 100644 > --- a/src/gallium/auxiliary/meson.build > +++ b/src/gallium/auxiliary/meson.build > @@ -231,20 +231,21 @@ files_libgallium = files( > 'util/u_bitmask.c', > 'util/u_bitmask.h', > 'util/u_blend.h', > 'util/u_blit.c', > 'util/u_blit.h', > 'util/u_blitter.c', > 'util/u_blitter.h', > 'util/u_box.h', > 'util/u_cache.c', > 'util/u_cache.h', > + 'util/u_cpu_suballoc.h', > 'util/u_debug_gallium.h', > 'util/u_debug_gallium.c', > 'util/u_debug_describe.c', > 'util/u_debug_describe.h', > 'util/u_debug_flush.c', > 'util/u_debug_flush.h', > 'util/u_debug_image.c', > 'util/u_debug_image.h', > 'util/u_debug_memory.c', > 'util/u_debug_refcnt.c', > diff --git a/src/gallium/auxiliary/util/u_cpu_suballoc.h b/src/gallium/auxiliary/util/u_cpu_suballoc.h > new file mode 100644 > index 00000000000..2373c1f7c70 > --- /dev/null > +++ b/src/gallium/auxiliary/util/u_cpu_suballoc.h > @@ -0,0 +1,90 @@ > +/************************************************************************** > + * > + * Copyright 2019 Advanced Micro Devices, Inc. > + * All Rights Reserved. > + * > + * Permission is hereby granted, free of charge, to any person obtaining a > + * copy of this software and associated documentation files (the > + * "Software"), to deal in the Software without restriction, including > + * without limitation the rights to use, copy, modify, merge, publish, > + * distribute, sub license, and/or sell copies of the Software, and to > + * permit persons to whom the Software is furnished to do so, subject to > + * the following conditions: > + * > + * The above copyright notice and this permission notice (including the > + * next paragraph) shall be included in all copies or substantial portions > + * of the Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS > + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF > + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. > + * IN NO EVENT SHALL AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR > + * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, > + * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE > + * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. > + * > + **************************************************************************/ > + > +/* A simple utility for suballocating out of malloc_aligned. */ > + > +#ifndef U_CPU_SUBALLOC_H > +#define U_CPU_SUBALLOC_H > + > +#include <stdint.h> > +#include "util/os_memory.h" > + > +struct u_cpu_suballoc { > + unsigned default_size; /* Default size of the buffer, in bytes. */ > + unsigned current_size; /* Current size of the buffer, in bytes. */ > + unsigned alignment; /* malloc alignment. */ > + unsigned offset; /* Offset pointing to the first unused byte. */ > + uint8_t *buffer; /* Pointer to the CPU buffer. */ > +}; > + > + > +static inline void > +u_cpu_suballoc_init(struct u_cpu_suballoc *alloc, unsigned default_size, > + unsigned alignment) > +{ > + memset(alloc, 0, sizeof(*alloc)); > + alloc->default_size = default_size; > + alloc->alignment = alignment; > +} > + > + > +static inline void > +u_cpu_suballoc_deinit(struct u_cpu_suballoc *alloc) > +{ > + os_free_aligned(alloc->buffer); > + alloc->buffer = NULL; > +} > + > + > +static inline void * > +u_cpu_suballoc(struct u_cpu_suballoc *alloc, unsigned size, unsigned alignment) > +{ > + unsigned offset = align(alloc->offset, alignment); > + > + /* Make sure we have enough space in the buffer for the sub-allocation. */ > + if (unlikely(!alloc->buffer || offset + size > alloc->current_size)) { > + os_free_aligned(alloc->buffer); So, if we can free the memory during a suballocation, how do we make sure that the previous allocations are valid? If they don't have to stay valid, why use a linear allocator at all? </blockquote><div> </div><div>The assumption is that previously allocated memory won't be accessed after the next call to u_cpu_suballoc. Yeah it's pretty fragile.</div><div> </div><div>Marek</div></div></div>