[01/30] split MRU ram list

From: Paolo Bonzini <pbonzini@redhat.com>

Outside the execution threads the normal, non-MRU-ized order of
the RAM blocks should always be enough.  So manage two separate
lists, which will have separate locking rules.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 arch_init.c |  1 +
 cpu-all.h   |  4 +++-
 exec.c      | 18 +++++++++++++-----
 3 files changed, 17 insertions(+), 6 deletions(-)

On 10/18/2012 09:29 AM, Juan Quintela wrote:
> From: Paolo Bonzini <pbonzini@redhat.com>
> 
> Outside the execution threads the normal, non-MRU-ized order of
> the RAM blocks should always be enough.  So manage two separate
> lists, which will have separate locking rules.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  arch_init.c |  1 +
>  cpu-all.h   |  4 +++-
>  exec.c      | 18 +++++++++++++-----
>  3 files changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/arch_init.c b/arch_init.c
> index e6effe8..4293557 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -48,6 +48,7 @@
>  #include "qemu/page_cache.h"
>  #include "qmp-commands.h"
>  #include "trace.h"
> +#include "cpu-all.h"
> 
>  #ifdef DEBUG_ARCH_INIT
>  #define DPRINTF(fmt, ...) \
> diff --git a/cpu-all.h b/cpu-all.h
> index 6aa7e58..6558a6f 100644
> --- a/cpu-all.h
> +++ b/cpu-all.h
> @@ -490,8 +490,9 @@ typedef struct RAMBlock {
>      ram_addr_t offset;
>      ram_addr_t length;
>      uint32_t flags;
> -    char idstr[256];
> +    QLIST_ENTRY(RAMBlock) next_mru;
>      QLIST_ENTRY(RAMBlock) next;
> +    char idstr[256];
>  #if defined(__linux__) && !defined(TARGET_S390X)
>      int fd;
>  #endif
> @@ -499,6 +500,7 @@ typedef struct RAMBlock {
> 
>  typedef struct RAMList {
>      uint8_t *phys_dirty;
> +    QLIST_HEAD(, RAMBlock) blocks_mru;
>      QLIST_HEAD(, RAMBlock) blocks;
>  } RAMList;
>  extern RAMList ram_list;
> diff --git a/exec.c b/exec.c
> index e63ad0d..718bbc2 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -56,6 +56,7 @@
>  #include "xen-mapcache.h"
>  #include "trace.h"
>  #endif
> +#include "cpu-all.h"
> 
>  #include "cputlb.h"
> 
> @@ -112,7 +113,10 @@ static uint8_t *code_gen_ptr;
>  int phys_ram_fd;
>  static int in_migration;
> 
> -RAMList ram_list = { .blocks = QLIST_HEAD_INITIALIZER(ram_list.blocks) };
> +RAMList ram_list = {
> +    .blocks = QLIST_HEAD_INITIALIZER(ram_list.blocks),
> +    .blocks_mru = QLIST_HEAD_INITIALIZER(ram_list.blocks_mru)
> +};
> 
>  static MemoryRegion *system_memory;
>  static MemoryRegion *system_io;
> @@ -633,6 +637,7 @@ bool tcg_enabled(void)
>  void cpu_exec_init_all(void)
>  {
>  #if !defined(CONFIG_USER_ONLY)
> +    qemu_mutex_init(&ram_list.mutex);
>      memory_map_init();
>      io_mem_init();
>  #endif
> @@ -2568,6 +2573,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
>      new_block->length = size;
> 
>      QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
> +    QLIST_INSERT_HEAD(&ram_list.blocks_mru, new_block, next_mru);
> 
>      ram_list.phys_dirty = g_realloc(ram_list.phys_dirty,
>                                         last_ram_offset() >> TARGET_PAGE_BITS);
> @@ -2595,6 +2601,7 @@ void qemu_ram_free_from_ptr(ram_addr_t addr)
>      QLIST_FOREACH(block, &ram_list.blocks, next) {
>          if (addr == block->offset) {
>              QLIST_REMOVE(block, next);
> +            QLIST_REMOVE(block, next_mru);
>              g_free(block);
>              return;
>          }
> @@ -2608,6 +2615,7 @@ void qemu_ram_free(ram_addr_t addr)
>      QLIST_FOREACH(block, &ram_list.blocks, next) {
>          if (addr == block->offset) {
>              QLIST_REMOVE(block, next);
> +            QLIST_REMOVE(block, next_mru);
>              if (block->flags & RAM_PREALLOC_MASK) {
>                  ;
>              } else if (mem_path) {
> @@ -2713,12 +2721,12 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
>  {
>      RAMBlock *block;
> 
> -    QLIST_FOREACH(block, &ram_list.blocks, next) {
> +    QLIST_FOREACH(block, &ram_list.blocks_mru, next_mru) {
>          if (addr - block->offset < block->length) {
>              /* Move this entry to to start of the list.  */
>              if (block != QLIST_FIRST(&ram_list.blocks)) {
> -                QLIST_REMOVE(block, next);
> -                QLIST_INSERT_HEAD(&ram_list.blocks, block, next);
> +                QLIST_REMOVE(block, next_mru);
> +                QLIST_INSERT_HEAD(&ram_list.blocks_mru, block, next_mru);
>              }
>              if (xen_enabled()) {
>                  /* We need to check if the requested address is in the RAM
> @@ -2813,7 +2821,7 @@ int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
>          return 0;
>      }
> 
> -    QLIST_FOREACH(block, &ram_list.blocks, next) {
> +    QLIST_FOREACH(block, &ram_list.blocks_mru, next_mru) {
>          /* This case append when the block is not mapped. */
>          if (block->host == NULL) {
>              continue;
> 
Reviewed-by: Orit Wasserman <owasserm@redhat.com>

On 18 October 2012 08:29, Juan Quintela <quintela@redhat.com> wrote:
> -RAMList ram_list = { .blocks = QLIST_HEAD_INITIALIZER(ram_list.blocks) };
> +RAMList ram_list = {
> +    .blocks = QLIST_HEAD_INITIALIZER(ram_list.blocks),
> +    .blocks_mru = QLIST_HEAD_INITIALIZER(ram_list.blocks_mru)
> +};

Maybe worth adding a comment explaining why we have the two lists,
to save people having to ferret around in the revision history later?

-- PMM