Re: 2.4.10pre7aa1

Dipankar Sarma (
Wed, 12 Sep 2001 16:34:26 +0530

In article <> you wrote:
> On Mon, 10 Sep 2001 17:54:17 +0200
> Andrea Arcangeli <> wrote:
>> Only in 2.4.10pre7aa1: 00_rcu-1
>> wait_for_rcu and call_rcu implementation (from IBM). I did some
>> modifications with respect to the original version from IBM.
>> In particular I dropped the vmalloc_rcu/kmalloc_rcu, the
>> rcu_head must always be allocated in the data structures, it has
>> to be a field of a class, rather than hiding it in the allocation
>> and playing dirty and risky with casts on a bigger allocation.

> Hi Andrea,

> Like the kernel threads approach, but AFAICT it won't work for the case of two CPUs running wait_for_rcu at the same time (on a 4-way or above).

The patch I submitted to Andrea had logic to make sure that
two CPUs don't execute wait_for_rcu() at the same time.
Somehow it seems to have got lost in Andrea's modifications.

I will look at that and submit a new patch to Andrea, if necessary.

As for wrappers, I am agnostic. However, I think sooner or later
people will start asking for them, if we go by our past experience.


Dipankar Sarma  <> Project:
Linux Technology Center, IBM Software Lab, Bangalore, India.
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