Re: [v3 0/9] parallelized "struct page" zeroing

From: David Miller
Date: Wed May 10 2017 - 11:21:20 EST


From: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Date: Wed, 10 May 2017 11:01:40 -0400

> Perhaps you are right, and I will measure on x86. But, I suspect hit
> can become unacceptable on some platfoms: there is an overhead of
> calling a function, even if it is leaf-optimized, and there is an
> overhead in memset() to check for alignments of size and address,
> types of setting (zeroing vs. non-zeroing), etc., that adds up
> quickly.

Another source of overhead on the sparc64 side is that we much
do memory barriers around the block initializiing stores. So
batching calls to memset() amortize that as well.