Messages in this thread | | | Date | Fri, 24 Feb 2006 18:52:31 +0000 | From | Christoph Hellwig <> | Subject | Re: [Patch 2/3] fast VMA recycling |
| |
On Thu, Feb 23, 2006 at 10:48:50AM +0100, Arjan van de Ven wrote: > On Thu, 2006-02-23 at 10:42 +0100, Andi Kleen wrote: > > On Thursday 23 February 2006 10:30, Arjan van de Ven wrote: > > > This patch adds a per task-struct cache of a free vma. > > > > > > In normal operation, it is a really common action during userspace mmap > > > or malloc to first allocate a vma, and then find out that it can be merged, > > > and thus free it again. In fact this is the case roughly 95% of the time. > > > > > > In addition, this patch allows code to "prepopulate" the cache, and > > > this is done as example for the x86_64 mmap codepath. The advantage of this > > > prepopulation is that the memory allocation (which is a sleeping operation > > > due to the GFP_KERNEL flag, potentially causing either a direct sleep or a > > > voluntary preempt sleep) will happen before the mmap_sem is taken, and thus > > > reduces lock hold time (and thus the contention potential) > > > > The slab fast path doesn't sleep. > > it does via might_sleep()
so turn of the voluntary preempt bullshit.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |