mariadb/mysys/my_lockmem.c
Marko Mäkelä 3794673111 MDEV-28836: Memory alignment cleanup
Table_cache_instance: Define the structure aligned at
the CPU cache line, and remove a pad[] data member.
Krunal Bauskar reported this to improve performance on ARMv8.

aligned_malloc(): Wrapper for the Microsoft _aligned_malloc()
and the ISO/IEC 9899:2011 <stdlib.h> aligned_alloc().
Note: The parameters are in the Microsoft order (size, alignment),
opposite of aligned_alloc(alignment, size).
Note: The standard defines that size must be an integer multiple
of alignment. It is enforced by AddressSanitizer but not by GNU libc
on Linux.

aligned_free(): Wrapper for the Microsoft _aligned_free() and
the standard free().

HAVE_ALIGNED_ALLOC: A new test. Unfortunately, support for
aligned_alloc() may still be missing on some platforms.
We will fall back to posix_memalign() for those cases.

HAVE_MEMALIGN: Remove, along with any use of the nonstandard memalign().

PFS_ALIGNEMENT (sic): Removed; we will use CPU_LEVEL1_DCACHE_LINESIZE.

PFS_ALIGNED: Defined using the C++11 keyword alignas.

buf_pool_t::page_hash_table::create(),
lock_sys_t::hash_table::create():
lock_sys_t::hash_table::resize(): Pad the allocation size to an
integer multiple of the alignment.

Reviewed by: Vladislav Vaintroub
2022-06-21 16:59:49 +03:00

99 lines
2.6 KiB
C

/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Copyright (c) 2022, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
/* Alloc a block of locked memory */
#include "mysys_priv.h"
#include "mysys_err.h"
#include "aligned.h"
#include <my_list.h>
#ifdef HAVE_MLOCK
struct st_mem_list
{
LIST list;
uchar *page;
uint size;
};
LIST *mem_list;
uchar *my_malloc_lock(uint size,myf MyFlags)
{
int success;
uint pagesize=sysconf(_SC_PAGESIZE);
uchar *ptr;
struct st_mem_list *element;
DBUG_ENTER("my_malloc_lock");
size=((size-1) & ~(pagesize-1))+pagesize;
if (!(ptr=aligned_malloc(size,pagesize)))
{
if (MyFlags & (MY_FAE+MY_WME))
my_error(EE_OUTOFMEMORY, MYF(ME_BELL+ME_FATAL), size);
DBUG_RETURN(0);
}
success = mlock((uchar*) ptr,size);
if (success != 0 && geteuid() == 0)
{
DBUG_PRINT("warning",("Failed to lock memory. errno %d\n",
errno));
fprintf(stderr, "Warning: Failed to lock memory. errno %d\n",
errno);
}
else
{
/* Add block in a list for munlock */
if (!(element=(struct st_mem_list*) my_malloc(sizeof(*element),MyFlags)))
{
(void) munlock((uchar*) ptr,size);
free(ptr);
DBUG_RETURN(0);
}
element->list.data=(uchar*) element;
element->page=ptr;
element->size=size;
mysql_mutex_lock(&THR_LOCK_malloc);
mem_list=list_add(mem_list,&element->list);
mysql_mutex_unlock(&THR_LOCK_malloc);
}
DBUG_RETURN(ptr);
}
void my_free_lock(uchar *ptr)
{
LIST *list;
struct st_mem_list *element=0;
mysql_mutex_lock(&THR_LOCK_malloc);
for (list=mem_list ; list ; list=list->next)
{
element=(struct st_mem_list*) list->data;
if (ptr == element->page)
{ /* Found locked mem */
(void) munlock((uchar*) ptr,element->size);
mem_list=list_delete(mem_list,list);
break;
}
}
mysql_mutex_unlock(&THR_LOCK_malloc);
my_free(element);
aligned_free(ptr); /* Free even if not locked */
}
#endif /* HAVE_MLOCK */