On Tue, Jun 26, 2012 at 8:51 PM, Eduardo Habkost <ehabk...@redhat.com> wrote:
> This make QEMU create files inside the -mem-path directory using
> more predictable names, and not remove them afterwards.
>
> This allow (for example) users or management layers to use numactl
> later, to set NUMA policy for the guest RAM.
>
> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> ---
> cpu-all.h | 1 +
> exec.c | 27 ++++++++++++++++++++++++++-
> qemu-options.hx | 12 ++++++++++++
> vl.c | 5 +++++
> 4 files changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/cpu-all.h b/cpu-all.h
> index 2beed5a..acd59ff 100644
> --- a/cpu-all.h
> +++ b/cpu-all.h
> @@ -490,6 +490,7 @@ typedef struct RAMList {
> extern RAMList ram_list;
>
> extern const char *mem_path;
> +extern bool keep_mem_path_files;
> extern bool mem_prealloc;
>
> /* Flags stored in the low bits of the TLB virtual address. These are
> diff --git a/exec.c b/exec.c
> index dcbe4e1..504e19f 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2377,6 +2377,28 @@ static int get_temp_fd(const char *path)
> return fd;
> }
>
> +/* Return FD to RAM block file, using the memory region name as filename
> + */
> +static int open_ramblock_file(RAMBlock *block, const char *path)
> +{
> + int fd;
> + char *filename;
> +
> + if (asprintf(&filename, "%s/%s", path, block->mr->name) == -1) {
asprintf() uses plain malloc() which is not tracked by our tracing
system. Please use g_malloc() and snprintf() or maybe
g_string_printf().
> + return -1;
> + }
> +
> + fd = open(filename, O_RDWR|O_CREAT);
> + if (fd < 0) {
> + perror("unable to open backing store for hugepages");
> + free(filename);
This needs to be converted to g_free() then.
> + return -1;
> + }
> + free(filename);
Ditto.
> +
> + return fd;
> +}
> +
> static void *file_ram_alloc(RAMBlock *block,
> size_t length,
> const char *path)
> @@ -2402,7 +2424,10 @@ static void *file_ram_alloc(RAMBlock *block,
> return NULL;
> }
>
> - fd = get_temp_fd(path);
> + if (keep_mem_path_files)
Missing braces needed by our CODING_STYLE.
> + fd = open_ramblock_file(block, path);
> + else
> + fd = get_temp_fd(path);
> if (fd < 0) {
> return NULL;
> }
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 8b66264..f2eb237 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -399,6 +399,18 @@ STEXI
> Allocate guest RAM from a temporarily created file in @var{path}.
> ETEXI
>
> +DEF("keep-mem-path-files", HAS_ARG, QEMU_OPTION_keep_mempath_files,
> + "-keep-mem-path-files Keep files created in -mem-path\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -keep-mem-path-files
> +Create the files for -mem-path using the memory region names, and don't
> remove
> +them afterwards.
> +
> +This allows further fine-tuning of NUMA policy for memory regions using
> +numactl.
> +ETEXI
> +
> +
> #ifdef MAP_POPULATE
> DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
> "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
> diff --git a/vl.c b/vl.c
> index 4e3403c..1dc595f 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -177,6 +177,8 @@ int display_remote = 0;
> const char* keyboard_layout = NULL;
> ram_addr_t ram_size;
> const char *mem_path = NULL;
> +bool keep_mem_path_files = false; /* Keep files created at mem_path.
> + * use memory region names as filename */
> #ifdef MAP_POPULATE
> bool mem_prealloc = false; /* force preallocation of physical target memory
> */
> #endif
> @@ -2671,6 +2673,9 @@ int main(int argc, char **argv, char **envp)
> case QEMU_OPTION_mempath:
> mem_path = optarg;
> break;
> + case QEMU_OPTION_keep_mempath_files:
> + keep_mem_path_files = true;
> + break;
> #ifdef MAP_POPULATE
> case QEMU_OPTION_mem_prealloc:
> mem_prealloc = true;
> --
> 1.7.10.4
>
>
