Messages in this thread | | | Date | Wed, 20 Oct 2010 23:54:34 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [tip:x86/mm] percpu: Introduce a read-mostly percpu API |
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On 10/20/2010 11:48 PM, Eric Dumazet wrote: > Le jeudi 21 octobre 2010 à 14:17 +0800, Shaohua Li a écrit : >> This isn't a previous bug. see >> #define DECLARE_PER_CPU_PAGE_ALIGNED(type, name) \ >> DECLARE_PER_CPU_SECTION(type, name, "..page_aligned") \ >> __aligned(PAGE_SIZE) >> the ..page_aligned is already page aligned. I add it is because it can make >> the .readmostly section guarantee to have no cache false sharing, because >> I add the . = ALIGN(PAGE_SIZE); before .readmostly section, and .page_aligned >> follows, but for sure this wates some memory. > > A small note: > > The __aligned(XXX) makes sure object _starts_ at XXX boundary, not that > following one will also use same alignment. Of course, we can argue that > we dont try to put in PAGE_ALIGNED section small objects, but still... > > Explicit .ALIGN() uses in .lds are more readable IMHO... >
There is. However, see again my previous note about SORT_BY_ALIGNMENT.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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