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memory: move preallocation code out of exec.c

Browse source 
So that backends can use it.

Since we need the page size for efficiency, move code to compute it
out of translate-all.c and into util/oslib-win32.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Paolo Bonzini 2014-05-14 17:43:21 +08:00 • committed by Michael S. Tsirkin
parent e1c57ab86f
commit 38183310be
6 changed files with 97 additions and 50 deletions
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73
util/oslib-posix.c
View file

@ -46,6 +46,7 @@ extern int daemon(int, int);
#else
# define QEMU_VMALLOC_ALIGN getpagesize()
#endif
#define HUGETLBFS_MAGIC 0x958458f6
#include <termios.h>
#include <unistd.h>
@ -58,9 +59,12 @@ extern int daemon(int, int);
#include "qemu/sockets.h"
#include <sys/mman.h>
#include <libgen.h>
#include <setjmp.h>
#include <sys/signal.h>
#ifdef CONFIG_LINUX
#include <sys/syscall.h>
#include <sys/vfs.h>
#endif
#ifdef __FreeBSD__
@ -332,3 +336,72 @@ char *qemu_get_exec_dir(void)
{
return g_strdup(exec_dir);
}
static sigjmp_buf sigjump;
static void sigbus_handler(int signal)
{
siglongjmp(sigjump, 1);
}
static size_t fd_getpagesize(int fd)
{
#ifdef CONFIG_LINUX
struct statfs fs;
int ret;
if (fd != -1) {
do {
ret = fstatfs(fd, &fs);
} while (ret != 0 && errno == EINTR);
if (ret == 0 && fs.f_type == HUGETLBFS_MAGIC) {
return fs.f_bsize;
}
}
#endif
return getpagesize();
}
void os_mem_prealloc(int fd, char *area, size_t memory)
{
int ret, i;
struct sigaction act, oldact;
sigset_t set, oldset;
size_t hpagesize = fd_getpagesize(fd);
memset(&act, 0, sizeof(act));
act.sa_handler = &sigbus_handler;
act.sa_flags = 0;
ret = sigaction(SIGBUS, &act, &oldact);
if (ret) {
perror("os_mem_prealloc: failed to install signal handler");
exit(1);
}
/* unblock SIGBUS */
sigemptyset(&set);
sigaddset(&set, SIGBUS);
pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
if (sigsetjmp(sigjump, 1)) {
fprintf(stderr, "os_mem_prealloc: failed to preallocate pages\n");
exit(1);
}
/* MAP_POPULATE silently ignores failures */
memory = (memory + hpagesize - 1) & -hpagesize;
for (i = 0; i < (memory/hpagesize); i++) {
memset(area + (hpagesize*i), 0, 1);
}
ret = sigaction(SIGBUS, &oldact, NULL);
if (ret) {
perror("os_mem_prealloc: failed to reinstall signal handler");
exit(1);
}
pthread_sigmask(SIG_SETMASK, &oldset, NULL);
}