On Fri, Oct 30, 2015 at 01:56:02PM +0800, Xiao Guangrong wrote:
> Currently file_ram_alloc() is designed for hugetlbfs, however, the memory
> of nvdimm can come from either raw pmem device eg, /dev/pmem, or the file
> locates at DAX enabled filesystem
>
> So this patch let it work on any kind of path
>
> Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
So this allows regular memory to be specified directly.
This needs to be split out and merged separately
from acpi/nvdimm bits.
Alternatively, if it's possible to use nvdimm with DAX fs
(similar to hugetlbfs), leave these patches off for now.
> ---
> exec.c | 56 +++++++++++++++++---------------------------------------
> 1 file changed, 17 insertions(+), 39 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 8af2570..3ca7e50 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1174,32 +1174,6 @@ void qemu_mutex_unlock_ramlist(void)
> }
>
> #ifdef __linux__
> -
> -#include <sys/vfs.h>
> -
> -#define HUGETLBFS_MAGIC 0x958458f6
> -
> -static long gethugepagesize(const char *path, Error **errp)
> -{
> - struct statfs fs;
> - int ret;
> -
> - do {
> - ret = statfs(path, &fs);
> - } while (ret != 0 && errno == EINTR);
> -
> - if (ret != 0) {
> - error_setg_errno(errp, errno, "failed to get page size of file %s",
> - path);
> - return 0;
> - }
> -
> - if (fs.f_type != HUGETLBFS_MAGIC)
> - fprintf(stderr, "Warning: path not on HugeTLBFS: %s\n", path);
> -
> - return fs.f_bsize;
> -}
> -
> static void *file_ram_alloc(RAMBlock *block,
> ram_addr_t memory,
> const char *path,
> @@ -1210,20 +1184,24 @@ static void *file_ram_alloc(RAMBlock *block,
> char *c;
> void *area;
> int fd;
> - uint64_t hpagesize;
> - Error *local_err = NULL;
> + uint64_t pagesize;
>
> - hpagesize = gethugepagesize(path, &local_err);
> - if (local_err) {
> - error_propagate(errp, local_err);
> + pagesize = qemu_file_get_page_size(path);
> + if (!pagesize) {
> + error_setg(errp, "can't get page size for %s", path);
> goto error;
> }
> - block->mr->align = hpagesize;
>
> - if (memory < hpagesize) {
> + if (pagesize == getpagesize()) {
> + fprintf(stderr, "Memory is not allocated from HugeTlbfs.\n");
> + }
> +
> + block->mr->align = pagesize;
> +
> + if (memory < pagesize) {
> error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to "
> - "or larger than huge page size 0x%" PRIx64,
> - memory, hpagesize);
> + "or larger than page size 0x%" PRIx64,
> + memory, pagesize);
> goto error;
> }
>
> @@ -1247,14 +1225,14 @@ static void *file_ram_alloc(RAMBlock *block,
> fd = mkstemp(filename);
> if (fd < 0) {
> error_setg_errno(errp, errno,
> - "unable to create backing store for hugepages");
> + "unable to create backing store for path %s", path);
> g_free(filename);
> goto error;
> }
> unlink(filename);
> g_free(filename);
Looks like we are still calling mkstemp/unlink here.
How does this work?
>
> - memory = ROUND_UP(memory, hpagesize);
> + memory = ROUND_UP(memory, pagesize);
>
> /*
> * ftruncate is not supported by hugetlbfs in older
> @@ -1266,10 +1244,10 @@ static void *file_ram_alloc(RAMBlock *block,
> perror("ftruncate");
> }
>
> - area = qemu_ram_mmap(fd, memory, hpagesize, block->flags & RAM_SHARED);
> + area = qemu_ram_mmap(fd, memory, pagesize, block->flags & RAM_SHARED);
> if (area == MAP_FAILED) {
> error_setg_errno(errp, errno,
> - "unable to map backing store for hugepages");
> + "unable to map backing store for path %s", path);
> close(fd);
> goto error;
> }
> --
> 1.8.3.1
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