The i915-fix seems to work. cyclictest has been running on the kernel for several hours now and has a maximum latency of 61us. On the previous kernel version without enabling the do_wbindvd-hack the maximum latency was above 2ms. Thanks. Christoph On Fri, Nov 8, 2013 at 11:15 PM, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: > Dear RT folks! > > I'm pleased to announce the v3.10.18-rt14 patch set. > > Changes since v3.10.18-rt13 > - a SLUB fix. The delayed free might use wrong kmem_cache structure. > - update to Yang Shi's memcontrol sleeping while atomic fix. Thanks you > Yang Shi. > - dropping the wbinvd in i915. The do_wbinvd module parameter is gone, > the fix from mainline has been backported. This has been compile > tested, some feedback would be nice. > > Known issues: > > - SLAB support not working > > - The cpsw network driver shows some issues. > > - bcache is disabled. > > - an ancient race (since we got sleeping spinlocks) where the > TASK_TRACED state is temporary replaced while waiting on a rw > lock and the task can't be traced. > > The delta patch against v3.10.18-rt14 is appended below and can be found > here: > https://www.kernel.org/pub/linux/kernel/projects/rt/3.10/incr/patch-3.10.18-rt13-rt14.patch.xz > > The RT patch against 3.10.18 can be found here: > > https://www.kernel.org/pub/linux/kernel/projects/rt/3.10/patch-3.10.18-rt14.patch.xz > > The split quilt queue is available at: > > https://www.kernel.org/pub/linux/kernel/projects/rt/3.10/patches-3.10.18-rt14.tar.xz > > Sebastian > > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index d62b80d..080b1b2 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -35,7 +35,6 @@ > #include <linux/swap.h> > #include <linux/pci.h> > #include <linux/dma-buf.h> > -#include <linux/module.h> > > static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj); > static void i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj); > @@ -2714,47 +2713,17 @@ static inline int fence_number(struct drm_i915_private *dev_priv, > return fence - dev_priv->fence_regs; > } > > -static bool do_wbinvd = true; > -module_param(do_wbinvd, bool, 0644); > -MODULE_PARM_DESC(do_wbinvd, "Do expensive synchronization. Say no after you pin each GPU process to the same CPU in order to lower the latency."); > - > -static void i915_gem_write_fence__ipi(void *data) > -{ > - wbinvd(); > -} > - > static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj, > struct drm_i915_fence_reg *fence, > bool enable) > { > - struct drm_device *dev = obj->base.dev; > - struct drm_i915_private *dev_priv = dev->dev_private; > - int fence_reg = fence_number(dev_priv, fence); > - > - /* In order to fully serialize access to the fenced region and > - * the update to the fence register we need to take extreme > - * measures on SNB+. In theory, the write to the fence register > - * flushes all memory transactions before, and coupled with the > - * mb() placed around the register write we serialise all memory > - * operations with respect to the changes in the tiler. Yet, on > - * SNB+ we need to take a step further and emit an explicit wbinvd() > - * on each processor in order to manually flush all memory > - * transactions before updating the fence register. > - */ > - if (HAS_LLC(obj->base.dev)) { > - if (do_wbinvd) { > -#ifdef CONFIG_PREEMPT_RT_FULL > - pr_err_once("WARNING! The i915 invalidates all caches which increases the latency."); > - pr_err_once("As a workaround use 'i915.do_wbinvd=no' and PIN each process doing "); > - pr_err_once("any kind of GPU activity to the same CPU to avoid problems."); > -#endif > - on_each_cpu(i915_gem_write_fence__ipi, NULL, 1); > - } > - } > - i915_gem_write_fence(dev, fence_reg, enable ? obj : NULL); > + struct drm_i915_private *dev_priv = obj->base.dev->dev_private; > + int reg = fence_number(dev_priv, fence); > + > + i915_gem_write_fence(obj->base.dev, reg, enable ? obj : NULL); > > if (enable) { > - obj->fence_reg = fence_reg; > + obj->fence_reg = reg; > fence->obj = obj; > list_move_tail(&fence->lru_list, &dev_priv->mm.fence_list); > } else { > diff --git a/localversion-rt b/localversion-rt > index 9f7d0bd..08b3e75 100644 > --- a/localversion-rt > +++ b/localversion-rt > @@ -1 +1 @@ > --rt13 > +-rt14 > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index f113cb7..2163f2f 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2436,10 +2436,11 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) > */ > static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) > { > - int cpu; > + int cpu, curcpu; > > /* Notify other cpus that system-wide "drain" is running */ > get_online_cpus(); > + curcpu = get_cpu_light(); > for_each_online_cpu(cpu) { > struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); > struct mem_cgroup *memcg; > @@ -2449,9 +2450,14 @@ static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) > continue; > if (!mem_cgroup_same_or_subtree(root_memcg, memcg)) > continue; > - if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) > - schedule_work_on(cpu, &stock->work); > + if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { > + if (cpu == curcpu) > + drain_local_stock(&stock->work); > + else > + schedule_work_on(cpu, &stock->work); > + } > } > + put_cpu_light(); > > if (!sync) > goto out; > diff --git a/mm/slub.c b/mm/slub.c > index 1378cd1..31c6f9f 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1428,13 +1428,13 @@ static void __free_slab(struct kmem_cache *s, struct page *page) > __free_memcg_kmem_pages(page, order); > } > > -static void free_delayed(struct kmem_cache *s, struct list_head *h) > +static void free_delayed(struct list_head *h) > { > while(!list_empty(h)) { > struct page *page = list_first_entry(h, struct page, lru); > > list_del(&page->lru); > - __free_slab(s, page); > + __free_slab(page->slab_cache, page); > } > } > > @@ -2007,7 +2007,7 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) > list_splice_init(&f->list, &tofree); > raw_spin_unlock(&f->lock); > local_irq_restore(flags); > - free_delayed(s, &tofree); > + free_delayed(&tofree); > oldpage = NULL; > pobjects = 0; > pages = 0; > @@ -2083,7 +2083,7 @@ static void flush_all(struct kmem_cache *s) > raw_spin_lock_irq(&f->lock); > list_splice_init(&f->list, &tofree); > raw_spin_unlock_irq(&f->lock); > - free_delayed(s, &tofree); > + free_delayed(&tofree); > } > } > > @@ -2331,7 +2331,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, > list_splice_init(&f->list, &tofree); > raw_spin_unlock(&f->lock); > local_irq_restore(flags); > - free_delayed(s, &tofree); > + free_delayed(&tofree); > return freelist; > > new_slab: > -- > To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
