view src/os/unix/ngx_freebsd_init.c @ 7985:ec2e6893caaa

Simplified sendfile(SF_NODISKIO) usage. Starting with FreeBSD 11, there is no need to use AIO operations to preload data into cache for sendfile(SF_NODISKIO) to work. Instead, sendfile() handles non-blocking loading data from disk by itself. It still can, however, return EBUSY if a page is already being loaded (for example, by a different process). If this happens, we now post an event for the next event loop iteration, so sendfile() is retried "after a short period", as manpage recommends. The limit of the number of EBUSY tolerated without any progress is preserved, but now it does not result in an alert, since on an idle system event loop iteration might be very short and EBUSY can happen many times in a row. Instead, SF_NODISKIO is simply disabled for one call once the limit is reached. With this change, sendfile(SF_NODISKIO) is now used automatically as long as sendfile() is enabled, and no longer requires "aio on;".
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 27 Dec 2021 19:48:33 +0300
parents 56fc55e32f23
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


/* FreeBSD 3.0 at least */
char    ngx_freebsd_kern_ostype[16];
char    ngx_freebsd_kern_osrelease[128];
int     ngx_freebsd_kern_osreldate;
int     ngx_freebsd_hw_ncpu;
int     ngx_freebsd_kern_ipc_somaxconn;
u_long  ngx_freebsd_net_inet_tcp_sendspace;

/* FreeBSD 4.9 */
int     ngx_freebsd_machdep_hlt_logical_cpus;


ngx_uint_t  ngx_freebsd_sendfile_nbytes_bug;
ngx_uint_t  ngx_freebsd_use_tcp_nopush;

ngx_uint_t  ngx_debug_malloc;


static ngx_os_io_t ngx_freebsd_io = {
    ngx_unix_recv,
    ngx_readv_chain,
    ngx_udp_unix_recv,
    ngx_unix_send,
    ngx_udp_unix_send,
    ngx_udp_unix_sendmsg_chain,
#if (NGX_HAVE_SENDFILE)
    ngx_freebsd_sendfile_chain,
    NGX_IO_SENDFILE
#else
    ngx_writev_chain,
    0
#endif
};


typedef struct {
    char        *name;
    void        *value;
    size_t       size;
    ngx_uint_t   exists;
} sysctl_t;


sysctl_t sysctls[] = {
    { "hw.ncpu",
      &ngx_freebsd_hw_ncpu,
      sizeof(ngx_freebsd_hw_ncpu), 0 },

    { "machdep.hlt_logical_cpus",
      &ngx_freebsd_machdep_hlt_logical_cpus,
      sizeof(ngx_freebsd_machdep_hlt_logical_cpus), 0 },

    { "net.inet.tcp.sendspace",
      &ngx_freebsd_net_inet_tcp_sendspace,
      sizeof(ngx_freebsd_net_inet_tcp_sendspace), 0 },

    { "kern.ipc.somaxconn",
      &ngx_freebsd_kern_ipc_somaxconn,
      sizeof(ngx_freebsd_kern_ipc_somaxconn), 0 },

    { NULL, NULL, 0, 0 }
};


void
ngx_debug_init(void)
{
#if (NGX_DEBUG_MALLOC)

#if __FreeBSD_version >= 500014 && __FreeBSD_version < 1000011
    _malloc_options = "J";
#elif __FreeBSD_version < 500014
    malloc_options = "J";
#endif

    ngx_debug_malloc = 1;

#else
    char  *mo;

    mo = getenv("MALLOC_OPTIONS");

    if (mo && ngx_strchr(mo, 'J')) {
        ngx_debug_malloc = 1;
    }
#endif
}


ngx_int_t
ngx_os_specific_init(ngx_log_t *log)
{
    int         version;
    size_t      size;
    ngx_err_t   err;
    ngx_uint_t  i;

    size = sizeof(ngx_freebsd_kern_ostype);
    if (sysctlbyname("kern.ostype",
                     ngx_freebsd_kern_ostype, &size, NULL, 0) == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                      "sysctlbyname(kern.ostype) failed");

        if (ngx_errno != NGX_ENOMEM) {
            return NGX_ERROR;
        }

        ngx_freebsd_kern_ostype[size - 1] = '\0';
    }

    size = sizeof(ngx_freebsd_kern_osrelease);
    if (sysctlbyname("kern.osrelease",
                     ngx_freebsd_kern_osrelease, &size, NULL, 0) == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                      "sysctlbyname(kern.osrelease) failed");

        if (ngx_errno != NGX_ENOMEM) {
            return NGX_ERROR;
        }

        ngx_freebsd_kern_osrelease[size - 1] = '\0';
    }


    size = sizeof(int);
    if (sysctlbyname("kern.osreldate",
                     &ngx_freebsd_kern_osreldate, &size, NULL, 0) == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                      "sysctlbyname(kern.osreldate) failed");
        return NGX_ERROR;
    }

    version = ngx_freebsd_kern_osreldate;


#if (NGX_HAVE_SENDFILE)

    /*
     * The determination of the sendfile() "nbytes bug" is complex enough.
     * There are two sendfile() syscalls: a new #393 has no bug while
     * an old #336 has the bug in some versions and has not in others.
     * Besides libc_r wrapper also emulates the bug in some versions.
     * There is no way to say exactly if syscall #336 in FreeBSD circa 4.6
     * has the bug.  We use the algorithm that is correct at least for
     * RELEASEs and for syscalls only (not libc_r wrapper).
     *
     * 4.6.1-RELEASE and below have the bug
     * 4.6.2-RELEASE and above have the new syscall
     *
     * We detect the new sendfile() syscall available at the compile time
     * to allow an old binary to run correctly on an updated FreeBSD system.
     */

#if (__FreeBSD__ == 4 && __FreeBSD_version >= 460102) \
    || __FreeBSD_version == 460002 || __FreeBSD_version >= 500039

    /* a new syscall without the bug */

    ngx_freebsd_sendfile_nbytes_bug = 0;

#else

    /* an old syscall that may have the bug */

    ngx_freebsd_sendfile_nbytes_bug = 1;

#endif

#endif /* NGX_HAVE_SENDFILE */


    if ((version < 500000 && version >= 440003) || version >= 500017) {
        ngx_freebsd_use_tcp_nopush = 1;
    }


    for (i = 0; sysctls[i].name; i++) {
        size = sysctls[i].size;

        if (sysctlbyname(sysctls[i].name, sysctls[i].value, &size, NULL, 0)
            == 0)
        {
            sysctls[i].exists = 1;
            continue;
        }

        err = ngx_errno;

        if (err == NGX_ENOENT) {
            continue;
        }

        ngx_log_error(NGX_LOG_ALERT, log, err,
                      "sysctlbyname(%s) failed", sysctls[i].name);
        return NGX_ERROR;
    }

    if (ngx_freebsd_machdep_hlt_logical_cpus) {
        ngx_ncpu = ngx_freebsd_hw_ncpu / 2;

    } else {
        ngx_ncpu = ngx_freebsd_hw_ncpu;
    }

    if (version < 600008 && ngx_freebsd_kern_ipc_somaxconn > 32767) {
        ngx_log_error(NGX_LOG_ALERT, log, 0,
                      "sysctl kern.ipc.somaxconn must be less than 32768");
        return NGX_ERROR;
    }

    ngx_tcp_nodelay_and_tcp_nopush = 1;

    ngx_os_io = ngx_freebsd_io;

    return NGX_OK;
}


void
ngx_os_specific_status(ngx_log_t *log)
{
    u_long      value;
    ngx_uint_t  i;

    ngx_log_error(NGX_LOG_NOTICE, log, 0, "OS: %s %s",
                  ngx_freebsd_kern_ostype, ngx_freebsd_kern_osrelease);

#ifdef __DragonFly_version
    ngx_log_error(NGX_LOG_NOTICE, log, 0,
                  "kern.osreldate: %d, built on %d",
                  ngx_freebsd_kern_osreldate, __DragonFly_version);
#else
    ngx_log_error(NGX_LOG_NOTICE, log, 0,
                  "kern.osreldate: %d, built on %d",
                  ngx_freebsd_kern_osreldate, __FreeBSD_version);
#endif

    for (i = 0; sysctls[i].name; i++) {
        if (sysctls[i].exists) {
            if (sysctls[i].size == sizeof(long)) {
                value = *(long *) sysctls[i].value;

            } else {
                value = *(int *) sysctls[i].value;
            }

            ngx_log_error(NGX_LOG_NOTICE, log, 0, "%s: %l",
                          sysctls[i].name, value);
        }
    }
}