diff mbox

[V6] fsdev: add IO throttle support to fsdev devices

Message ID 1477066919-35979-1-git-send-email-pradeep.jagadeesh@huawei.com
State New
Headers show

Commit Message

Pradeep Jagadeesh Oct. 21, 2016, 4:21 p.m. UTC 
Signed-off-by: Pradeep Jagadeesh <pradeep.jagadeesh@huawei.com>
---
 fsdev/Makefile.objs         |   1 +
 fsdev/file-op-9p.h          |   3 +
 fsdev/qemu-fsdev-opts.c     |  76 +++++++++++++++++++++++
 fsdev/qemu-fsdev-throttle.c | 147 ++++++++++++++++++++++++++++++++++++++++++++
 fsdev/qemu-fsdev-throttle.h |  37 +++++++++++
 hw/9pfs/9p-local.c          |   9 ++-
 hw/9pfs/9p.c                |   6 ++
 hw/9pfs/cofile.c            |   5 ++
 8 files changed, 282 insertions(+), 2 deletions(-)
 create mode 100644 fsdev/qemu-fsdev-throttle.c
 create mode 100644 fsdev/qemu-fsdev-throttle.h

This adds the support for the 9p-local driver.
For now this functionality can be enabled only through qemu cli options.
QMP interface and support to other drivers need further extensions.
To make it simple for other drivers, the throttle code has been put in
separate files.

v1 -> v2:

-Fixed FsContext redeclaration issue
-Removed couple of function declarations from 9p-throttle.h
-Fixed some of the .help messages

v2 -> v3:

-Addressed follwing comments by Claudio Fontana
 -Removed redundant memset calls in fsdev_throttle_configure_iolimits function
 -Checking throttle structure validity before initializing other structures
  in fsdev_throttle_configure_iolimits

-Addressed following comments by Greg Kurz
 -Moved the code from 9pfs directory to fsdev directory, because the throttling
  is for the fsdev devices.Renamed the files and functions to fsdev_ from 9pfs_
 -Renamed throttling cli options to throttling.*, as in QMP cli options
 -Removed some of the unwanted .h files from qemu-fsdev-throttle.[ch]
 -Using throttle_enabled() function to set the thottle enabled flag for fsdev.

v3 -> v4:

-Addressed following comments by Alberto Garcia
 -Removed the unwanted locking and other data structures in qemu-fsdev-throttle.[ch]

-Addressed following comments by Greg Kurz
 -Removed fsdev_iolimitsenable/disable functions, instead using throttle_enabled function

v4 -> V5:
 -Fixed the issue with the larger block size accounting.
 (i.e, when the 9pfs mounted using msize=xxx option)

V5 -> V6:
-Addressed the comments by Alberto Garcia 
 -Removed the fsdev_throttle_timer_cb() 
 -Simplified the  fsdev_throttle_schedule_next_request() as suggested

Comments

Alberto Garcia Oct. 21, 2016, 5:47 p.m. UTC | #1 
On Fri 21 Oct 2016 06:21:59 PM CEST, Pradeep Jagadeesh <pradeepkiruvale@gmail.com> wrote:

> +static bool fsdev_throttle_check_for_wait(FsThrottle *fst, bool is_write)
> +{
> +   return  throttle_schedule_timer(&fst->ts, &fst->tt, is_write);
             ^
There's an extra whitespace there.

> +static void fsdev_throttle_schedule_next_request(FsThrottle *fst, bool is_write)
> +{
> +   if (!qemu_co_queue_empty(&fst->throttled_reqs[is_write])) {
> +        if (fsdev_throttle_check_for_wait(fst, is_write)) {
> +            return;
> +        }
> +   }
> +       qemu_co_queue_next(&fst->throttled_reqs[is_write]);
> +}

That is wrong, you're calling qemu_co_queue_next() even if the queue is
empty. That line should be inside the 'if' block.

I still think that -after the changes you made in v6- you could put the
contents of that whole function inside fsdev_co_throttle_request(), and
at the same time get rid of fsdev_throttle_check_for_wait() and call
throttle_schedule_timer() directly. The resulting code will be smaller
and probably easier to read. But those are just style decisions.

> +static int get_num_bytes(struct iovec *iov, int iovcnt)
> +{
> +    int i;
> +    int bytes = 0;
> +
> +    for (i = 0; i < iovcnt; i++) {
> +        bytes += iov[i].iov_len;
> +    }
> +    return bytes;
> +}

I overlooked that in my previous review, but 'bytes' should be unsigned
(both here and in fsdev_co_throttle_request).

I still have to review the init/cleanup functions (I'll try to do it on
monday) but else the code looks fine now.

Berto
Pradeep Jagadeesh Oct. 24, 2016, 6:02 a.m. UTC | #2 
> On Fri 21 Oct 2016 06:21:59 PM CEST, Pradeep Jagadeesh <pradeepkiruvale@gmail.com> wrote:
>
>> +static bool fsdev_throttle_check_for_wait(FsThrottle *fst, bool is_write)
>> +{
>> +   return  throttle_schedule_timer(&fst->ts, &fst->tt, is_write);
>              ^
> There's an extra whitespace there.
Removed
>
>> +static void fsdev_throttle_schedule_next_request(FsThrottle *fst, bool is_write)
>> +{
>> +   if (!qemu_co_queue_empty(&fst->throttled_reqs[is_write])) {
>> +        if (fsdev_throttle_check_for_wait(fst, is_write)) {
>> +            return;
>> +        }
>> +   }
>> +       qemu_co_queue_next(&fst->throttled_reqs[is_write]);
>> +}
>
> That is wrong, you're calling qemu_co_queue_next() even if the queue is
> empty. That line should be inside the 'if' block.
>
Done!
> I still think that -after the changes you made in v6- you could put the
> contents of that whole function inside fsdev_co_throttle_request(), and
> at the same time get rid of fsdev_throttle_check_for_wait() and call
> throttle_schedule_timer() directly. The resulting code will be smaller
> and probably easier to read. But those are just style decisions.
I just would like to keep these functions.
>
>> +static int get_num_bytes(struct iovec *iov, int iovcnt)
>> +{
>> +    int i;
>> +    int bytes = 0;
>> +
>> +    for (i = 0; i < iovcnt; i++) {
>> +        bytes += iov[i].iov_len;
>> +    }
>> +    return bytes;
>> +}
>
> I overlooked that in my previous review, but 'bytes' should be unsigned
> (both here and in fsdev_co_throttle_request).
Done!
>
> I still have to review the init/cleanup functions (I'll try to do it on
> monday) but else the code looks fine now.
>
Ok, I am out of office for whole week. I can send the next patch only on 
next saturday/sunday. Please let me know all your comments by then.

-Pradeep
> Berto
>
diff mbox

Patch

diff --git a/fsdev/Makefile.objs b/fsdev/Makefile.objs
index 1b120a4..2c6da2d 100644
--- a/fsdev/Makefile.objs
+++ b/fsdev/Makefile.objs
@@ -7,6 +7,7 @@  common-obj-y = qemu-fsdev-dummy.o
 endif
 common-obj-y += qemu-fsdev-opts.o
 
+common-obj-y += qemu-fsdev-throttle.o
 # Toplevel always builds this; targets without virtio will put it in
 # common-obj-y
 common-obj-$(CONFIG_ALL) += qemu-fsdev-dummy.o
diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 6db9fea..33fe822 100644
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -17,6 +17,7 @@ 
 #include <dirent.h>
 #include <utime.h>
 #include <sys/vfs.h>
+#include "qemu-fsdev-throttle.h"
 
 #define SM_LOCAL_MODE_BITS    0600
 #define SM_LOCAL_DIR_MODE_BITS    0700
@@ -74,6 +75,7 @@  typedef struct FsDriverEntry {
     char *path;
     int export_flags;
     FileOperations *ops;
+    FsThrottle fst;
 } FsDriverEntry;
 
 typedef struct FsContext
@@ -83,6 +85,7 @@  typedef struct FsContext
     int export_flags;
     struct xattr_operations **xops;
     struct extended_ops exops;
+    FsThrottle *fst;
     /* fs driver specific data */
     void *private;
 } FsContext;
diff --git a/fsdev/qemu-fsdev-opts.c b/fsdev/qemu-fsdev-opts.c
index 1dd8c7a..395d497 100644
--- a/fsdev/qemu-fsdev-opts.c
+++ b/fsdev/qemu-fsdev-opts.c
@@ -37,6 +37,82 @@  static QemuOptsList qemu_fsdev_opts = {
         }, {
             .name = "sock_fd",
             .type = QEMU_OPT_NUMBER,
+        }, {
+            .name = "throttling.iops-total",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit total I/O operations per second",
+        },{
+            .name = "throttling.iops-read",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit read operations per second",
+        },{
+            .name = "throttling.iops-write",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit write operations per second",
+        },{
+            .name = "throttling.bps-total",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit total bytes per second",
+        },{
+            .name = "throttling.bps-read",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit read bytes per second",
+        },{
+            .name = "throttling.bps-write",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit write bytes per second",
+        },{
+            .name = "throttling.iops-total-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "I/O operations burst",
+        },{
+            .name = "throttling.iops-read-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "I/O operations read burst",
+        },{
+            .name = "throttling.iops-write-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "I/O operations write burst",
+        },{
+            .name = "throttling.bps-total-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "total bytes burst",
+        },{
+            .name = "throttling.bps-read-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "total bytes read burst",
+        },{
+            .name = "throttling.bps-write-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "total bytes write burst",
+        },{
+            .name = "throttling.iops-total-max-length",
+            .type = QEMU_OPT_NUMBER,
+            .help = "length of the iops-total-max burst period, in seconds",
+        },{
+            .name = "throttling.iops-read-max-length",
+            .type = QEMU_OPT_NUMBER,
+            .help = "length of the iops-read-max burst period, in seconds",
+        },{
+            .name = "throttling.iops-write-max-length",
+            .type = QEMU_OPT_NUMBER,
+            .help = "length of the iops-write-max burst period, in seconds",
+        },{
+            .name = "throttling.bps-total-max-length",
+            .type = QEMU_OPT_NUMBER,
+            .help = "length of the bps-total-max burst period, in seconds",
+        },{
+            .name = "throttling.bps-read-max-length",
+            .type = QEMU_OPT_NUMBER,
+            .help = "length of the bps-read-max burst period, in seconds",
+        },{
+            .name = "throttling.bps-write-max-length",
+            .type = QEMU_OPT_NUMBER,
+            .help = "length of the bps-write-max burst period, in seconds",
+        },{
+            .name = "throttling.iops-size",
+            .type = QEMU_OPT_NUMBER,
+            .help = "when limiting by iops max size of an I/O in bytes",
         },
 
         { /*End of list */ }
diff --git a/fsdev/qemu-fsdev-throttle.c b/fsdev/qemu-fsdev-throttle.c
new file mode 100644
index 0000000..6adb423
--- /dev/null
+++ b/fsdev/qemu-fsdev-throttle.c
@@ -0,0 +1,147 @@ 
+/*
+ * Fsdev Throttle
+ *
+ * Copyright (C) 2016 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Pradeep Jagadeesh <pradeep.jagadeesh@huawei.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.
+ *
+ * See the COPYING file in the top-level directory for details.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qemu-fsdev-throttle.h"
+
+static bool fsdev_throttle_check_for_wait(FsThrottle *fst, bool is_write)
+{
+   return  throttle_schedule_timer(&fst->ts, &fst->tt, is_write);
+}
+
+static void fsdev_throttle_schedule_next_request(FsThrottle *fst, bool is_write)
+{
+   if (!qemu_co_queue_empty(&fst->throttled_reqs[is_write])) {
+        if (fsdev_throttle_check_for_wait(fst, is_write)) {
+            return;
+        }
+   }
+       qemu_co_queue_next(&fst->throttled_reqs[is_write]);
+}
+
+static void fsdev_throttle_read_timer_cb(void *opaque)
+{
+    FsThrottle *fst = opaque;
+    qemu_co_enter_next(&fst->throttled_reqs[false]);
+}
+
+static void fsdev_throttle_write_timer_cb(void *opaque)
+{
+    FsThrottle *fst = opaque;
+    qemu_co_enter_next(&fst->throttled_reqs[true]);
+}
+
+static void fsdev_parse_io_limit_opts(QemuOpts *opts, FsThrottle *fst)
+{
+    fst->cfg.buckets[THROTTLE_BPS_TOTAL].avg =
+          qemu_opt_get_number(opts, "throttling.bps-total", 0);
+    fst->cfg.buckets[THROTTLE_BPS_READ].avg  =
+          qemu_opt_get_number(opts, "throttling.bps-read", 0);
+    fst->cfg.buckets[THROTTLE_BPS_WRITE].avg =
+          qemu_opt_get_number(opts, "throttling.bps-write", 0);
+    fst->cfg.buckets[THROTTLE_OPS_TOTAL].avg =
+          qemu_opt_get_number(opts, "throttling.iops-total", 0);
+    fst->cfg.buckets[THROTTLE_OPS_READ].avg =
+          qemu_opt_get_number(opts, "throttling.iops-read", 0);
+    fst->cfg.buckets[THROTTLE_OPS_WRITE].avg =
+          qemu_opt_get_number(opts, "throttling.iops-write", 0);
+
+    fst->cfg.buckets[THROTTLE_BPS_TOTAL].max =
+          qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
+    fst->cfg.buckets[THROTTLE_BPS_READ].max  =
+          qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
+    fst->cfg.buckets[THROTTLE_BPS_WRITE].max =
+          qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
+    fst->cfg.buckets[THROTTLE_OPS_TOTAL].max =
+          qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
+    fst->cfg.buckets[THROTTLE_OPS_READ].max =
+          qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
+    fst->cfg.buckets[THROTTLE_OPS_WRITE].max =
+          qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
+
+    fst->cfg.buckets[THROTTLE_BPS_TOTAL].burst_length =
+          qemu_opt_get_number(opts, "throttling.bps-total-max-length", 1);
+    fst->cfg.buckets[THROTTLE_BPS_READ].burst_length  =
+          qemu_opt_get_number(opts, "throttling.bps-read-max-length", 1);
+    fst->cfg.buckets[THROTTLE_BPS_WRITE].burst_length =
+          qemu_opt_get_number(opts, "throttling.bps-write-max-length", 1);
+    fst->cfg.buckets[THROTTLE_OPS_TOTAL].burst_length =
+          qemu_opt_get_number(opts, "throttling.iops-total-max-length", 1);
+    fst->cfg.buckets[THROTTLE_OPS_READ].burst_length =
+          qemu_opt_get_number(opts, "throttling.iops-read-max-length", 1);
+    fst->cfg.buckets[THROTTLE_OPS_WRITE].burst_length =
+          qemu_opt_get_number(opts, "throttling.iops-write-max-length", 1);
+    fst->cfg.op_size =
+          qemu_opt_get_number(opts, "throttling.iops-size", 0);
+}
+
+int fsdev_throttle_configure_iolimits(QemuOpts *opts, FsThrottle *fst)
+{
+    Error *err = NULL;
+
+    /* Parse and set populate the cfg structure */
+    fsdev_parse_io_limit_opts(opts, fst);
+
+    if (!throttle_is_valid(&fst->cfg, &err)) {
+        error_reportf_err(err, "Throttle configuration is not valid: ");
+        return -1;
+    }
+    if (throttle_enabled(&fst->cfg)) {
+        g_assert((fst->aioctx = qemu_get_aio_context()));
+        throttle_init(&fst->ts);
+        throttle_timers_init(&fst->tt,
+                             fst->aioctx,
+                             QEMU_CLOCK_REALTIME,
+                             fsdev_throttle_read_timer_cb,
+                             fsdev_throttle_write_timer_cb,
+                             fst);
+        throttle_config(&fst->ts, &fst->tt, &fst->cfg);
+        qemu_co_queue_init(&fst->throttled_reqs[0]);
+        qemu_co_queue_init(&fst->throttled_reqs[1]);
+   }
+   return 0;
+}
+
+static int get_num_bytes(struct iovec *iov, int iovcnt)
+{
+    int i;
+    int bytes = 0;
+
+    for (i = 0; i < iovcnt; i++) {
+        bytes += iov[i].iov_len;
+    }
+    return bytes;
+}
+
+void coroutine_fn fsdev_co_throttle_request(FsThrottle *fst, bool is_write,
+                            struct iovec *iov, int iovcnt)
+{
+    if (throttle_enabled(&fst->cfg)) {
+        int bytes = get_num_bytes(iov, iovcnt);
+        bool must_wait = fsdev_throttle_check_for_wait(fst, is_write);
+        if (must_wait || !qemu_co_queue_empty(&fst->throttled_reqs[is_write])) {
+            qemu_co_queue_wait(&fst->throttled_reqs[is_write]);
+       }
+       throttle_account(&fst->ts, is_write, bytes);
+
+       fsdev_throttle_schedule_next_request(fst, is_write);
+    }
+}
+
+void fsdev_throttle_cleanup(FsThrottle *fst)
+{
+    throttle_timers_destroy(&fst->tt);
+}
diff --git a/fsdev/qemu-fsdev-throttle.h b/fsdev/qemu-fsdev-throttle.h
new file mode 100644
index 0000000..df4e608
--- /dev/null
+++ b/fsdev/qemu-fsdev-throttle.h
@@ -0,0 +1,37 @@ 
+/*
+ * Fsdev Throttle
+ *
+ * Copyright (C) 2016 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Pradeep Jagadeesh <pradeep.jagadeesh@huawei.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.
+ *
+ * See the COPYING file in the top-level directory for details.
+ *
+ */
+
+#ifndef _FSDEV_THROTTLE_H
+#define _FSDEV_THROTTLE_H
+
+#include "block/aio.h"
+#include "qemu/main-loop.h"
+#include "qemu/coroutine.h"
+#include "qemu/throttle.h"
+
+typedef struct FsThrottle {
+    ThrottleState ts;
+    ThrottleTimers tt;
+    AioContext   *aioctx;
+    ThrottleConfig cfg;
+    CoQueue      throttled_reqs[2];
+} FsThrottle;
+
+int  fsdev_throttle_configure_iolimits(QemuOpts *, FsThrottle *);
+
+void coroutine_fn fsdev_co_throttle_request(FsThrottle *fst, bool is_write,
+                            struct iovec *iov, int iovcnt);
+
+void fsdev_throttle_cleanup(FsThrottle *);
+#endif /* _FSDEV_THROTTLE_H */
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 3f271fc..54459f2 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -436,8 +436,8 @@  static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
                              const struct iovec *iov,
                              int iovcnt, off_t offset)
 {
-    ssize_t ret
-;
+    ssize_t ret;
+
 #ifdef CONFIG_PREADV
     ret = pwritev(fs->fd, iov, iovcnt, offset);
 #else
@@ -1240,6 +1240,11 @@  static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
         error_report("fsdev: No path specified");
         return -1;
     }
+
+    if (fsdev_throttle_configure_iolimits(opts, &fse->fst) < 0) {
+        return -1;
+    }
+
     fse->path = g_strdup(path);
 
     return 0;
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index dfe293d..ccf6d0c 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -3490,6 +3490,9 @@  int v9fs_device_realize_common(V9fsState *s, Error **errp)
         error_setg(errp, "share path %s is not a directory", fse->path);
         goto out;
     }
+
+    s->ctx.fst = &fse->fst;
+
     v9fs_path_free(&path);
 
     rc = 0;
@@ -3504,6 +3507,9 @@  out:
 
 void v9fs_device_unrealize_common(V9fsState *s, Error **errp)
 {
+    if (throttle_enabled(&s->ctx.fst->cfg)) {
+        fsdev_throttle_cleanup(s->ctx.fst);
+    }
     g_free(s->ctx.fs_root);
     g_free(s->tag);
 }
diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
index 10343c0..039031d 100644
--- a/hw/9pfs/cofile.c
+++ b/hw/9pfs/cofile.c
@@ -16,6 +16,7 @@ 
 #include "qemu/thread.h"
 #include "qemu/coroutine.h"
 #include "coth.h"
+#include "fsdev/qemu-fsdev-throttle.h"
 
 int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
                    V9fsStatDotl *v9stat)
@@ -245,6 +246,8 @@  int v9fs_co_pwritev(V9fsPDU *pdu, V9fsFidState *fidp,
     if (v9fs_request_cancelled(pdu)) {
         return -EINTR;
     }
+
+    fsdev_co_throttle_request(s->ctx.fst, true, iov, iovcnt);
     v9fs_co_run_in_worker(
         {
             err = s->ops->pwritev(&s->ctx, &fidp->fs, iov, iovcnt, offset);
@@ -264,6 +267,8 @@  int v9fs_co_preadv(V9fsPDU *pdu, V9fsFidState *fidp,
     if (v9fs_request_cancelled(pdu)) {
         return -EINTR;
     }
+
+    fsdev_co_throttle_request(s->ctx.fst, false, iov, iovcnt);
     v9fs_co_run_in_worker(
         {
             err = s->ops->preadv(&s->ctx, &fidp->fs, iov, iovcnt, offset);