On 06/15/2016 01:43 PM, Peter Zijlstra wrote:
On Tue, Jun 14, 2016 at 06:48:08PM -0400, Waiman Long wrote:even the reduced maximum of about 16k (32-bit) or 1G (64-bit) should be more than enough for the foreseeable future.So what happens if I manage to create 16k+ threads on my 32bit kernel and get them all to do mmap() or so at the same time. That doesn't seem too far fetched. Then again, with double that (the current limit) that doesn't seem impossible either.
To hit the limit, we need to have all the threads calling down_write() at exactly the same instance in time which, I think, is pretty hard to do. Also, I don't believe you will ever see a 16k-cpu massive SMP system running on 32-bit kernel. I can imagine such a system running on 64-bit kernel, but certainly not 32-bit.
Cheers, Longman -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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