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;".

diff --git a/auto/os/freebsd b/auto/os/freebsd
index 937ca204e6d0ce7679ea2a71289a5e1e450e922f..870bac4b3e6fdf87502731b2af255476f08906bf 100644 (file)
--- a/auto/os/freebsd
+++ b/auto/os/freebsd
@@ -44,12 +44,10 @@ if [ $osreldate -gt 300007 ]; then
     CORE_SRCS="$CORE_SRCS $FREEBSD_SENDFILE_SRCS"
 fi
 
-if [ $NGX_FILE_AIO = YES ]; then
-    if [ $osreldate -gt 502103 ]; then
-        echo " + sendfile()'s SF_NODISKIO found"
+if [ $osreldate -gt 1100093 ]; then
+    echo " + sendfile()'s SF_NODISKIO found"
 
-        have=NGX_HAVE_AIO_SENDFILE . auto/have
-    fi
+    have=NGX_HAVE_SENDFILE_NODISKIO . auto/have
 fi
 
 # POSIX semaphores

diff --git a/src/core/ngx_buf.h b/src/core/ngx_buf.h
index 4b665629c7f3ce9c911147e76d38e8e90861dded..fdcd0cddf68637a75e432e3872f4e16a111807bf 100644 (file)
--- a/src/core/ngx_buf.h
+++ b/src/core/ngx_buf.h
@@ -90,9 +90,6 @@ struct ngx_output_chain_ctx_s {
 
 #if (NGX_HAVE_FILE_AIO || NGX_COMPAT)
     ngx_output_chain_aio_pt      aio_handler;
-#if (NGX_HAVE_AIO_SENDFILE || NGX_COMPAT)
-    ssize_t                    (*aio_preload)(ngx_buf_t *file);
-#endif
 #endif
 
 #if (NGX_THREADS || NGX_COMPAT)

diff --git a/src/core/ngx_connection.h b/src/core/ngx_connection.h
index 4716da492e90bcaf54a4ddb79e95bfd9b1253f93..8cc14755ad46cbc82a1bf5464c043c2baa6c9ee2 100644 (file)
--- a/src/core/ngx_connection.h
+++ b/src/core/ngx_connection.h
@@ -185,7 +185,7 @@ struct ngx_connection_s {
 
     unsigned            need_last_buf:1;
 
-#if (NGX_HAVE_AIO_SENDFILE || NGX_COMPAT)
+#if (NGX_HAVE_SENDFILE_NODISKIO || NGX_COMPAT)
     unsigned            busy_count:2;
 #endif
 

diff --git a/src/core/ngx_module.h b/src/core/ngx_module.h
index 8cf3210e8eacbabf826cb2a49ed0a68d2bec537a..6fb455426b3bbdc796e2921127b85a746e700f47 100644 (file)
--- a/src/core/ngx_module.h
+++ b/src/core/ngx_module.h
@@ -41,7 +41,7 @@
 #define NGX_MODULE_SIGNATURE_3   "0"
 #endif
 
-#if (NGX_HAVE_AIO_SENDFILE || NGX_COMPAT)
+#if (NGX_HAVE_SENDFILE_NODISKIO || NGX_COMPAT)
 #define NGX_MODULE_SIGNATURE_4   "1"
 #else
 #define NGX_MODULE_SIGNATURE_4   "0"

diff --git a/src/core/ngx_output_chain.c b/src/core/ngx_output_chain.c
index fd4603b1973fb7ac7117553c7a9a3e897898eee0..41267eefff2bd7d3ee1c82696a81027455a805bb 100644 (file)
--- a/src/core/ngx_output_chain.c
+++ b/src/core/ngx_output_chain.c
@@ -29,10 +29,6 @@
 
 static ngx_inline ngx_int_t
     ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf);
-#if (NGX_HAVE_AIO_SENDFILE)
-static ngx_int_t ngx_output_chain_aio_setup(ngx_output_chain_ctx_t *ctx,
-    ngx_file_t *file);
-#endif
 static ngx_int_t ngx_output_chain_add_copy(ngx_pool_t *pool,
     ngx_chain_t **chain, ngx_chain_t *in);
 static ngx_int_t ngx_output_chain_align_file_buf(ngx_output_chain_ctx_t *ctx,
@@ -283,12 +279,6 @@ ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf)
         buf->in_file = 0;
     }
 
-#if (NGX_HAVE_AIO_SENDFILE)
-    if (ctx->aio_preload && buf->in_file) {
-        (void) ngx_output_chain_aio_setup(ctx, buf->file);
-    }
-#endif
-
     if (ctx->need_in_memory && !ngx_buf_in_memory(buf)) {
         return 0;
     }
@@ -301,28 +291,6 @@ ngx_output_chain_as_is(ngx_output_chain_ctx_t *ctx, ngx_buf_t *buf)
 }
 
 
-#if (NGX_HAVE_AIO_SENDFILE)
-
-static ngx_int_t
-ngx_output_chain_aio_setup(ngx_output_chain_ctx_t *ctx, ngx_file_t *file)
-{
-    ngx_event_aio_t  *aio;
-
-    if (file->aio == NULL && ngx_file_aio_init(file, ctx->pool) != NGX_OK) {
-        return NGX_ERROR;
-    }
-
-    aio = file->aio;
-
-    aio->data = ctx->filter_ctx;
-    aio->preload_handler = ctx->aio_preload;
-
-    return NGX_OK;
-}
-
-#endif
-
-
 static ngx_int_t
 ngx_output_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
     ngx_chain_t *in)

diff --git a/src/event/ngx_event.h b/src/event/ngx_event.h
index 97f9673c90dac71c00ab75a08108438b3cd4febd..51b8361321a70c5acd567c85c75ca75ef0c16868 100644 (file)
--- a/src/event/ngx_event.h
+++ b/src/event/ngx_event.h
@@ -147,10 +147,6 @@ struct ngx_event_aio_s {
 
     ngx_fd_t                   fd;
 
-#if (NGX_HAVE_AIO_SENDFILE || NGX_COMPAT)
-    ssize_t                  (*preload_handler)(ngx_buf_t *file);
-#endif
-
 #if (NGX_HAVE_EVENTFD)
     int64_t                    res;
 #endif

diff --git a/src/http/ngx_http_copy_filter_module.c b/src/http/ngx_http_copy_filter_module.c
index b47e4afa750838dd023fb7429256f5f1ab567be8..bd3028bc76817a1106de8e4fce47485516ffc2c6 100644 (file)
--- a/src/http/ngx_http_copy_filter_module.c
+++ b/src/http/ngx_http_copy_filter_module.c
@@ -19,10 +19,6 @@ typedef struct {
 static void ngx_http_copy_aio_handler(ngx_output_chain_ctx_t *ctx,
     ngx_file_t *file);
 static void ngx_http_copy_aio_event_handler(ngx_event_t *ev);
-#if (NGX_HAVE_AIO_SENDFILE)
-static ssize_t ngx_http_copy_aio_sendfile_preload(ngx_buf_t *file);
-static void ngx_http_copy_aio_sendfile_event_handler(ngx_event_t *ev);
-#endif
 #endif
 #if (NGX_THREADS)
 static ngx_int_t ngx_http_copy_thread_handler(ngx_thread_task_t *task,
@@ -128,9 +124,6 @@ ngx_http_copy_filter(ngx_http_request_t *r, ngx_chain_t *in)
 #if (NGX_HAVE_FILE_AIO)
         if (ngx_file_aio && clcf->aio == NGX_HTTP_AIO_ON) {
             ctx->aio_handler = ngx_http_copy_aio_handler;
-#if (NGX_HAVE_AIO_SENDFILE)
-            ctx->aio_preload = ngx_http_copy_aio_sendfile_preload;
-#endif
         }
 #endif
 
@@ -207,81 +200,6 @@ ngx_http_copy_aio_event_handler(ngx_event_t *ev)
     ngx_http_run_posted_requests(c);
 }
 
-
-#if (NGX_HAVE_AIO_SENDFILE)
-
-static ssize_t
-ngx_http_copy_aio_sendfile_preload(ngx_buf_t *file)
-{
-    ssize_t                  n;
-    static u_char            buf[1];
-    ngx_event_aio_t         *aio;
-    ngx_http_request_t      *r;
-    ngx_output_chain_ctx_t  *ctx;
-
-    aio = file->file->aio;
-    r = aio->data;
-
-    if (r->aio) {
-        /*
-         * tolerate sendfile() calls if another operation is already
-         * running; this can happen due to subrequests, multiple calls
-         * of the next body filter from a filter, or in HTTP/2 due to
-         * a write event on the main connection
-         */
-
-        return NGX_AGAIN;
-    }
-
-    n = ngx_file_aio_read(file->file, buf, 1, file->file_pos, NULL);
-
-    if (n == NGX_AGAIN) {
-        aio->handler = ngx_http_copy_aio_sendfile_event_handler;
-
-        r->main->blocked++;
-        r->aio = 1;
-
-        ctx = ngx_http_get_module_ctx(r, ngx_http_copy_filter_module);
-        ctx->aio = 1;
-    }
-
-    return n;
-}
-
-
-static void
-ngx_http_copy_aio_sendfile_event_handler(ngx_event_t *ev)
-{
-    ngx_event_aio_t     *aio;
-    ngx_connection_t    *c;
-    ngx_http_request_t  *r;
-
-    aio = ev->data;
-    r = aio->data;
-    c = r->connection;
-
-    r->main->blocked--;
-    r->aio = 0;
-    ev->complete = 0;
-
-#if (NGX_HTTP_V2)
-
-    if (r->stream) {
-        /*
-         * for HTTP/2, update write event to make sure processing will
-         * reach the main connection to handle sendfile() preload
-         */
-
-        c->write->ready = 1;
-        c->write->active = 0;
-    }
-
-#endif
-
-    c->write->handler(c->write);
-}
-
-#endif
 #endif
 
 

diff --git a/src/os/unix/ngx_freebsd_sendfile_chain.c b/src/os/unix/ngx_freebsd_sendfile_chain.c
index 750c12fc3538306c896ac16de8ffb8fbc13b794b..c939f6ad62e143ac9f87b3de552e16b5d96216d6 100644 (file)
--- a/src/os/unix/ngx_freebsd_sendfile_chain.c
+++ b/src/os/unix/ngx_freebsd_sendfile_chain.c
@@ -32,23 +32,22 @@
 ngx_chain_t *
 ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 {
-    int               rc, flags;
-    off_t             send, prev_send, sent;
-    size_t            file_size;
-    ssize_t           n;
-    ngx_uint_t        eintr, eagain;
-    ngx_err_t         err;
-    ngx_buf_t        *file;
-    ngx_event_t      *wev;
-    ngx_chain_t      *cl;
-    ngx_iovec_t       header, trailer;
-    struct sf_hdtr    hdtr;
-    struct iovec      headers[NGX_IOVS_PREALLOCATE];
-    struct iovec      trailers[NGX_IOVS_PREALLOCATE];
-#if (NGX_HAVE_AIO_SENDFILE)
-    ngx_uint_t        ebusy;
-    ngx_event_aio_t  *aio;
+    int              rc, flags;
+    off_t            send, prev_send, sent;
+    size_t           file_size;
+    ssize_t          n;
+    ngx_err_t        err;
+    ngx_buf_t       *file;
+    ngx_uint_t       eintr, eagain;
+#if (NGX_HAVE_SENDFILE_NODISKIO)
+    ngx_uint_t       ebusy;
 #endif
+    ngx_event_t     *wev;
+    ngx_chain_t     *cl;
+    ngx_iovec_t      header, trailer;
+    struct sf_hdtr   hdtr;
+    struct iovec     headers[NGX_IOVS_PREALLOCATE];
+    struct iovec     trailers[NGX_IOVS_PREALLOCATE];
 
     wev = c->write;
 
@@ -77,11 +76,6 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
     eagain = 0;
     flags = 0;
 
-#if (NGX_HAVE_AIO_SENDFILE && NGX_SUPPRESS_WARN)
-    aio = NULL;
-    file = NULL;
-#endif
-
     header.iovs = headers;
     header.nalloc = NGX_IOVS_PREALLOCATE;
 
@@ -90,7 +84,7 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
     for ( ;; ) {
         eintr = 0;
-#if (NGX_HAVE_AIO_SENDFILE)
+#if (NGX_HAVE_SENDFILE_NODISKIO)
         ebusy = 0;
 #endif
         prev_send = send;
@@ -179,9 +173,8 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
             sent = 0;
 
-#if (NGX_HAVE_AIO_SENDFILE)
-            aio = file->file->aio;
-            flags = (aio && aio->preload_handler) ? SF_NODISKIO : 0;
+#if (NGX_HAVE_SENDFILE_NODISKIO)
+            flags = (c->busy_count <= 2) ? SF_NODISKIO : 0;
 #endif
 
             rc = sendfile(file->file->fd, c->fd, file->file_pos,
@@ -199,7 +192,7 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
                     eintr = 1;
                     break;
 
-#if (NGX_HAVE_AIO_SENDFILE)
+#if (NGX_HAVE_SENDFILE_NODISKIO)
                 case NGX_EBUSY:
                     ebusy = 1;
                     break;
@@ -252,41 +245,30 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
         in = ngx_chain_update_sent(in, sent);
 
-#if (NGX_HAVE_AIO_SENDFILE)
+#if (NGX_HAVE_SENDFILE_NODISKIO)
 
         if (ebusy) {
             if (sent == 0) {
                 c->busy_count++;
 
-                if (c->busy_count > 2) {
-                    ngx_log_error(NGX_LOG_ALERT, c->log, 0,
-                                  "sendfile(%V) returned busy again",
-                                  &file->file->name);
-
-                    c->busy_count = 0;
-                    aio->preload_handler = NULL;
-
-                    send = prev_send;
-                    continue;
-                }
+                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                               "sendfile() busy, count:%d", c->busy_count);
 
             } else {
                 c->busy_count = 0;
             }
 
-            n = aio->preload_handler(file);
-
-            if (n > 0) {
-                send = prev_send + sent;
-                continue;
+            if (wev->posted) {
+                ngx_delete_posted_event(wev);
             }
 
+            ngx_post_event(wev, &ngx_posted_next_events);
+
+            wev->ready = 0;
             return in;
         }
 
-        if (flags == SF_NODISKIO) {
-            c->busy_count = 0;
-        }
+        c->busy_count = 0;
 
 #endif