windowsaio: add best effort cache invalidation

[fio.git] / engines / windowsaio.c

diff --git a/engines/windowsaio.c b/engines/windowsaio.c
index f5cb04838a31f70dc6cf801239e33df16800f54c..2b12ddd01f69c85258ee7739ff90ade6c038be91 100644 (file)
--- a/engines/windowsaio.c
+++ b/engines/windowsaio.c
@@ -35,17 +35,7 @@ struct thread_ctx {
        struct windowsaio_data *wd;
 };
 
-static BOOL timeout_expired(DWORD start_count, DWORD end_count);
-static int fio_windowsaio_getevents(struct thread_data *td, unsigned int min,
-                               unsigned int max, const struct timespec *t);
-static struct io_u *fio_windowsaio_event(struct thread_data *td, int event);
-static int fio_windowsaio_queue(struct thread_data *td,
-                                 struct io_u *io_u);
-static void fio_windowsaio_cleanup(struct thread_data *td);
 static DWORD WINAPI IoCompletionRoutine(LPVOID lpParameter);
-static int fio_windowsaio_init(struct thread_data *td);
-static int fio_windowsaio_open_file(struct thread_data *td, struct fio_file *f);
-static int fio_windowsaio_close_file(struct thread_data fio_unused *td, struct fio_file *f);
 
 static int fio_windowsaio_init(struct thread_data *td)
 {
@@ -152,6 +142,43 @@ static void fio_windowsaio_cleanup(struct thread_data *td)
        }
 }
 
+static int windowsaio_invalidate_cache(struct fio_file *f)
+{
+       DWORD error;
+       DWORD isharemode = (FILE_SHARE_DELETE | FILE_SHARE_READ |
+                       FILE_SHARE_WRITE);
+       HANDLE ihFile;
+       int rc = 0;
+
+       /*
+        * Encourage Windows to drop cached parts of a file by temporarily
+        * opening it for non-buffered access. Note: this will only work when
+        * the following is the only thing with the file open on the whole
+        * system.
+        */
+       dprint(FD_IO, "windowaio: attempt invalidate cache for %s\n",
+                       f->file_name);
+       ihFile = CreateFile(f->file_name, 0, isharemode, NULL, OPEN_EXISTING,
+                       FILE_FLAG_NO_BUFFERING, NULL);
+
+       if (ihFile != INVALID_HANDLE_VALUE) {
+               if (!CloseHandle(ihFile)) {
+                       error = GetLastError();
+                       log_info("windowsaio: invalidation fd close %s "
+                                "failed: error %d\n", f->file_name, error);
+                       rc = 1;
+               }
+       } else {
+               error = GetLastError();
+               if (error != ERROR_FILE_NOT_FOUND) {
+                       log_info("windowsaio: cache invalidation of %s failed: "
+                                       "error %d\n", f->file_name, error);
+                       rc = 1;
+               }
+       }
+
+       return rc;
+}
 
 static int fio_windowsaio_open_file(struct thread_data *td, struct fio_file *f)
 {
@@ -180,13 +207,26 @@ static int fio_windowsaio_open_file(struct thread_data *td, struct fio_file *f)
 
        /*
         * Inform Windows whether we're going to be doing sequential or
-        * random io so it can tune the Cache Manager
+        * random IO so it can tune the Cache Manager
         */
-       if (td->o.td_ddir == TD_DDIR_READ  ||
-               td->o.td_ddir == TD_DDIR_WRITE)
-               flags |= FILE_FLAG_SEQUENTIAL_SCAN;
-       else
+       switch (td->o.fadvise_hint) {
+       case F_ADV_TYPE:
+               if (td_random(td))
+                       flags |= FILE_FLAG_RANDOM_ACCESS;
+               else
+                       flags |= FILE_FLAG_SEQUENTIAL_SCAN;
+               break;
+       case F_ADV_RANDOM:
                flags |= FILE_FLAG_RANDOM_ACCESS;
+               break;
+       case F_ADV_SEQUENTIAL:
+               flags |= FILE_FLAG_SEQUENTIAL_SCAN;
+               break;
+       case F_ADV_NONE:
+               break;
+       default:
+               log_err("fio: unknown fadvise type %d\n", td->o.fadvise_hint);
+       }
 
        if (!td_write(td) || read_only)
                access = GENERIC_READ;
@@ -198,6 +238,12 @@ static int fio_windowsaio_open_file(struct thread_data *td, struct fio_file *f)
        else
                openmode = OPEN_EXISTING;
 
+       /* If we're going to use direct I/O, Windows will try and invalidate
+        * its cache at that point so there's no need to do it here */
+       if (td->o.invalidate_cache && !td->o.odirect) {
+               windowsaio_invalidate_cache(f);
+       }
+
        f->hFile = CreateFile(f->file_name, access, sharemode,
                NULL, openmode, flags, NULL);