Commit 38183310 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Michael S. Tsirkin
Browse files

memory: move preallocation code out of exec.c 



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: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarHu Tao <hutao@cn.fujitsu.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent e1c57ab8

exec.c

+1 −43
Original line number Diff line number Diff line
@@ -1011,13 +1011,6 @@ static long gethugepagesize(const char *path) 
    return fs.f_bsize;

}



static sigjmp_buf sigjump;



static void sigbus_handler(int signal)

{

    siglongjmp(sigjump, 1);

}



static void *file_ram_alloc(RAMBlock *block,

                            ram_addr_t memory,

                            const char *path)
@@ -1082,42 +1075,7 @@ static void *file_ram_alloc(RAMBlock *block, 
    }



    if (mem_prealloc) {

        int ret, i;

        struct sigaction act, oldact;

        sigset_t set, oldset;



        memset(&act, 0, sizeof(act));

        act.sa_handler = &sigbus_handler;

        act.sa_flags = 0;



        ret = sigaction(SIGBUS, &act, &oldact);

        if (ret) {

            perror("file_ram_alloc: 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, "file_ram_alloc: failed to preallocate pages\n");

            exit(1);

        }



        /* MAP_POPULATE silently ignores failures */

        for (i = 0; i < (memory/hpagesize); i++) {

            memset(area + (hpagesize*i), 0, 1);

        }



        ret = sigaction(SIGBUS, &oldact, NULL);

        if (ret) {

            perror("file_ram_alloc: failed to reinstall signal handler");

            exit(1);

        }



        pthread_sigmask(SIG_SETMASK, &oldset, NULL);

        os_mem_prealloc(fd, area, memory);

    }



    block->fd = fd;

include/qemu/osdep.h

+2 −0
Original line number Diff line number Diff line
@@ -251,4 +251,6 @@ void qemu_init_auxval(char **envp); 


void qemu_set_tty_echo(int fd, bool echo);



void os_mem_prealloc(int fd, char *area, size_t sz);



#endif

include/sysemu/os-win32.h

+2 −0
Original line number Diff line number Diff line
@@ -89,6 +89,8 @@ static inline void os_setup_post(void) {} 
void os_set_line_buffering(void);

static inline void os_set_proc_name(const char *dummy) {}



size_t getpagesize(void);



#if !defined(EPROTONOSUPPORT)

# define EPROTONOSUPPORT EINVAL

#endif

translate-all.c

+0 −7
Original line number Diff line number Diff line
@@ -295,14 +295,7 @@ void page_size_init(void) 
{

    /* NOTE: we can always suppose that qemu_host_page_size >=

       TARGET_PAGE_SIZE */

#ifdef _WIN32

    SYSTEM_INFO system_info;



    GetSystemInfo(&system_info);

    qemu_real_host_page_size = system_info.dwPageSize;

#else

    qemu_real_host_page_size = getpagesize();

#endif

    if (qemu_host_page_size == 0) {

        qemu_host_page_size = qemu_real_host_page_size;

    }

util/oslib-posix.c

+73 −0
Original line number Diff line number Diff line
@@ -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);

}