From 758d90e161382c134b7cbd5f724df4de02f3c67e Mon Sep 17 00:00:00 2001 From: Tomasz Figa Date: Mon, 19 Jun 2017 00:53:43 -0300 Subject: [PATCH] [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 Acked-by: Marek Szyprowski Acked-by: Sakari Ailus Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-async.c | 5 +++-- drivers/media/v4l2-core/v4l2-ctrls.c | 26 ++++++++++++---------- drivers/media/v4l2-core/v4l2-event.c | 8 ++++--- drivers/media/v4l2-core/v4l2-ioctl.c | 7 +++--- drivers/media/v4l2-core/v4l2-subdev.c | 8 ++++--- drivers/media/v4l2-core/videobuf2-dma-sg.c | 8 +++---- 6 files changed, 35 insertions(+), 27 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index c16200c88417..851f128eba22 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -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 36eede3ff098..dd1db678718c 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -19,6 +19,7 @@ */ #include +#include #include #include #include @@ -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 a75df6cb141f..968c2eb08b5a 100644 --- a/drivers/media/v4l2-core/v4l2-event.c +++ b/drivers/media/v4l2-core/v4l2-event.c @@ -21,6 +21,7 @@ #include #include +#include #include #include #include @@ -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 ce40183d9daa..6eabd915aff6 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -12,6 +12,7 @@ * Mauro Carvalho Chehab (version 2) */ +#include #include #include #include @@ -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 da78497ae5ed..43fefa73e0a3 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -17,6 +17,7 @@ */ #include +#include #include #include #include @@ -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 8e8798a74760..5defa1f22ca2 100644 --- 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); } -- 2.20.1