Messages in this thread | | | Subject | Re: [v2 3/5] mm: add "zero" argument to vmemmap allocators | From | Pasha Tatashin <> | Date | Wed, 3 May 2017 11:05:45 -0400 |
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Hi Dave,
Thank you for the review. I will address your comment and update patchset..
Pasha
On 05/03/2017 10:34 AM, David Miller wrote: > From: Pavel Tatashin <pasha.tatashin@oracle.com> > Date: Fri, 24 Mar 2017 15:19:50 -0400 > >> Allow clients to request non-zeroed memory from vmemmap allocator. >> The following two public function have a new boolean argument called zero: >> >> __vmemmap_alloc_block_buf() >> vmemmap_alloc_block() >> >> When zero is true, memory that is allocated by memblock allocator is zeroed >> (the current behavior), when argument is false, the memory is not zeroed. >> >> This change allows for optimizations where client knows when it is better >> to zero memory: may be later when other CPUs are started, or may be client >> is going to set every byte in the allocated memory, so no need to zero >> memory beforehand. >> >> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> >> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> > > I think when you add a new argument that can adjust behavior, you > should add the new argument but retain exactly the current behavior in > the existing calls. > > Then later you can piece by piece change behavior, and document properly > in the commit message what is happening and why the transformation is > legal. > > Here, you are adding the new boolean to __earlyonly_bootmem_alloc() and > then making sparse_mem_maps_populate_node() pass false, which changes > behavior such that it doesn't get zero'd memory any more. > > Please make one change at a time. Otherwise review and bisection is > going to be difficult. > > -- > To unsubscribe from this list: send the line "unsubscribe sparclinux" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
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