[media] v4l2-core: Use kvmalloc() for potentially big allocations

There are multiple places where arrays or otherwise variable sized
buffer are allocated through V4L2 core code, including things like
controls, memory pages, staging buffers for ioctls and so on. Such
allocations can potentially require an order > 0 allocation from the
page allocator, which is not guaranteed to be fulfilled and is likely to
fail on a system with severe memory fragmentation (e.g. a system with
very long uptime).

Since the memory being allocated is intended to be used by the CPU
exclusively, we can consider using vmalloc() as a fallback and this is
exactly what the recently merged kvmalloc() helpers do. A kmalloc() call
is still attempted, even for order > 0 allocations, but it is done
with __GFP_NORETRY and __GFP_NOWARN, with expectation of failing if
requested memory is not available instantly. Only then the vmalloc()
fallback is used. This should give us fast and more reliable allocations
even on systems with higher memory pressure and/or more fragmentation,
while still retaining the same performance level on systems not
suffering from such conditions.

While at it, replace explicit array size calculations on changed
allocations with kvmalloc_array().

Purposedly not touching videobuf1, as it is deprecated, has only few
users remaining and would rather be seen removed instead.

Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index c16200c88417b151c8751d050aa60633b8d7bc1b..851f128eba2219ad397ff327e9ff344a7703a51e 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -12,6 +12,7 @@
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/list.h>
+#include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
@@ -210,7 +211,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
        if (!notifier->v4l2_dev)
                return;
 
-       dev = kmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL);
+       dev = kvmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL);
        if (!dev) {
                dev_err(notifier->v4l2_dev->dev,
                        "Failed to allocate device cache!\n");
@@ -266,7 +267,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
                }
                put_device(d);
        }
-       kfree(dev);
+       kvfree(dev);
 
        notifier->v4l2_dev = NULL;
 

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 36eede3ff0981ca401fb46400c7ae1b6eab64699..dd1db678718c80568c6520b69e4e7b34d22df7b1 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -19,6 +19,7 @@
  */
 
 #include <linux/ctype.h>
+#include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <media/v4l2-ioctl.h>
@@ -1746,8 +1747,9 @@ int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
        INIT_LIST_HEAD(&hdl->ctrls);
        INIT_LIST_HEAD(&hdl->ctrl_refs);
        hdl->nr_of_buckets = 1 + nr_of_controls_hint / 8;
-       hdl->buckets = kcalloc(hdl->nr_of_buckets, sizeof(hdl->buckets[0]),
-                              GFP_KERNEL);
+       hdl->buckets = kvmalloc_array(hdl->nr_of_buckets,
+                                     sizeof(hdl->buckets[0]),
+                                     GFP_KERNEL | __GFP_ZERO);
        hdl->error = hdl->buckets ? 0 : -ENOMEM;
        return hdl->error;
 }
@@ -1774,9 +1776,9 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
                list_del(&ctrl->node);
                list_for_each_entry_safe(sev, next_sev, &ctrl->ev_subs, node)
                        list_del(&sev->node);
-               kfree(ctrl);
+               kvfree(ctrl);
        }
-       kfree(hdl->buckets);
+       kvfree(hdl->buckets);
        hdl->buckets = NULL;
        hdl->cached = NULL;
        hdl->error = 0;
@@ -2024,7 +2026,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
                 is_array)
                sz_extra += 2 * tot_ctrl_size;
 
-       ctrl = kzalloc(sizeof(*ctrl) + sz_extra, GFP_KERNEL);
+       ctrl = kvzalloc(sizeof(*ctrl) + sz_extra, GFP_KERNEL);
        if (ctrl == NULL) {
                handler_set_err(hdl, -ENOMEM);
                return NULL;
@@ -2073,7 +2075,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
        }
 
        if (handler_new_ref(hdl, ctrl)) {
-               kfree(ctrl);
+               kvfree(ctrl);
                return NULL;
        }
        mutex_lock(hdl->lock);
@@ -2843,8 +2845,8 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
                return class_check(hdl, cs->which);
 
        if (cs->count > ARRAY_SIZE(helper)) {
-               helpers = kmalloc_array(cs->count, sizeof(helper[0]),
-                                       GFP_KERNEL);
+               helpers = kvmalloc_array(cs->count, sizeof(helper[0]),
+                                        GFP_KERNEL);
                if (helpers == NULL)
                        return -ENOMEM;
        }
@@ -2896,7 +2898,7 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
        }
 
        if (cs->count > ARRAY_SIZE(helper))
-               kfree(helpers);
+               kvfree(helpers);
        return ret;
 }
 EXPORT_SYMBOL(v4l2_g_ext_ctrls);
@@ -3098,8 +3100,8 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
                return class_check(hdl, cs->which);
 
        if (cs->count > ARRAY_SIZE(helper)) {
-               helpers = kmalloc_array(cs->count, sizeof(helper[0]),
-                                       GFP_KERNEL);
+               helpers = kvmalloc_array(cs->count, sizeof(helper[0]),
+                                        GFP_KERNEL);
                if (!helpers)
                        return -ENOMEM;
        }
@@ -3176,7 +3178,7 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
        }
 
        if (cs->count > ARRAY_SIZE(helper))
-               kfree(helpers);
+               kvfree(helpers);
        return ret;
 }
 

diff --git a/drivers/media/v4l2-core/v4l2-event.c b/drivers/media/v4l2-core/v4l2-event.c
index a75df6cb141fdf1466baa323507da29d28e78617..968c2eb08b5aba52e18e66221a09b1f351b73337 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-event.c
+++ b/drivers/media/v4l2-core/v4l2-event.c
@@ -21,6 +21,7 @@
 #include <media/v4l2-fh.h>
 #include <media/v4l2-event.h>
 
+#include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/export.h>
@@ -214,7 +215,8 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
        if (elems < 1)
                elems = 1;
 
-       sev = kzalloc(sizeof(*sev) + sizeof(struct v4l2_kevent) * elems, GFP_KERNEL);
+       sev = kvzalloc(sizeof(*sev) + sizeof(struct v4l2_kevent) * elems,
+                      GFP_KERNEL);
        if (!sev)
                return -ENOMEM;
        for (i = 0; i < elems; i++)
@@ -232,7 +234,7 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
        spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
 
        if (found_ev) {
-               kfree(sev);
+               kvfree(sev);
                return 0; /* Already listening */
        }
 
@@ -304,7 +306,7 @@ int v4l2_event_unsubscribe(struct v4l2_fh *fh,
        if (sev && sev->ops && sev->ops->del)
                sev->ops->del(sev);
 
-       kfree(sev);
+       kvfree(sev);
 
        return 0;
 }

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index ce40183d9daaa8be2aa3b2b56c04c8b23829496e..6eabd915aff63203cd865ea4b914f696d399d1a6 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -12,6 +12,7 @@
  *              Mauro Carvalho Chehab <mchehab@infradead.org> (version 2)
  */
 
+#include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -2817,7 +2818,7 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg,
                        parg = sbuf;
                } else {
                        /* too big to allocate from stack */
-                       mbuf = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL);
+                       mbuf = kvmalloc(_IOC_SIZE(cmd), GFP_KERNEL);
                        if (NULL == mbuf)
                                return -ENOMEM;
                        parg = mbuf;
@@ -2866,7 +2867,7 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg,
                 * array) fits into sbuf (so that mbuf will still remain
                 * unused up to here).
                 */
-               mbuf = kmalloc(array_size, GFP_KERNEL);
+               mbuf = kvmalloc(array_size, GFP_KERNEL);
                err = -ENOMEM;
                if (NULL == mbuf)
                        goto out_array_args;
@@ -2911,7 +2912,7 @@ out_array_args:
        }
 
 out:
-       kfree(mbuf);
+       kvfree(mbuf);
        return err;
 }
 EXPORT_SYMBOL(video_usercopy);

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index da78497ae5ed2f0944a20c9992eaa4265917b175..43fefa73e0a3f64f852a9ee75a608f75005de308 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/ioctl.h>
+#include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/videodev2.h>
@@ -577,13 +578,14 @@ v4l2_subdev_alloc_pad_config(struct v4l2_subdev *sd)
        if (!sd->entity.num_pads)
                return NULL;
 
-       cfg = kcalloc(sd->entity.num_pads, sizeof(*cfg), GFP_KERNEL);
+       cfg = kvmalloc_array(sd->entity.num_pads, sizeof(*cfg),
+                            GFP_KERNEL | __GFP_ZERO);
        if (!cfg)
                return NULL;
 
        ret = v4l2_subdev_call(sd, pad, init_cfg, cfg);
        if (ret < 0 && ret != -ENOIOCTLCMD) {
-               kfree(cfg);
+               kvfree(cfg);
                return NULL;
        }
 
@@ -593,7 +595,7 @@ EXPORT_SYMBOL_GPL(v4l2_subdev_alloc_pad_config);
 
 void v4l2_subdev_free_pad_config(struct v4l2_subdev_pad_config *cfg)
 {
-       kfree(cfg);
+       kvfree(cfg);
 }
 EXPORT_SYMBOL_GPL(v4l2_subdev_free_pad_config);
 #endif /* CONFIG_MEDIA_CONTROLLER */

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 8e8798a7476036f07b10aa08974c59a6163ba651..5defa1f22ca2db3e2586b78d72cfae99909fbcd2 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -120,8 +120,8 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
        buf->num_pages = size >> PAGE_SHIFT;
        buf->dma_sgt = &buf->sg_table;
 
-       buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
-                            GFP_KERNEL);
+       buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
+                                   GFP_KERNEL | __GFP_ZERO);
        if (!buf->pages)
                goto fail_pages_array_alloc;
 
@@ -165,7 +165,7 @@ fail_table_alloc:
        while (num_pages--)
                __free_page(buf->pages[num_pages]);
 fail_pages_alloc:
-       kfree(buf->pages);
+       kvfree(buf->pages);
 fail_pages_array_alloc:
        kfree(buf);
        return ERR_PTR(-ENOMEM);
@@ -187,7 +187,7 @@ static void vb2_dma_sg_put(void *buf_priv)
                sg_free_table(buf->dma_sgt);
                while (--i >= 0)
                        __free_page(buf->pages[i]);
-               kfree(buf->pages);
+               kvfree(buf->pages);
                put_device(buf->dev);
                kfree(buf);
        }