Messages in this thread | | | Date | Thu, 25 Aug 2005 17:13:05 +0200 | From | Eric Dumazet <> | Subject | Re: [PATCH] removes filp_count_lock and changes nr_files type to atomic_t |
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Nick Piggin a écrit :
> OK, well I would prefer you do the proper atomic operations throughout > where it "really matters" in file_table.c, and do your lazy synchronize > with just the sysctl exported value. >
But... I got complains about atomic_read(&counter) being 'an atomic op' (untrue), so my second patch just doesnt touch the path where nr_files was read.
Furthermore, a lazy sync would mean to change sysctl proc_handler for "file-nr" to perform a synchronize before calling proc_dointvec, this would be really obscure.
> Unless the fs people had a problem with that. > > And you may as well get rid of the atomic_inc_return which can be more > expensive on some platforms and doesn't buy you much. > atomic_inc; > atomic_read; > Should be enough if you don't care about lost updates here, yeah? >
You mean :
atomic_inc(&counter); lazeyvalue = atomic_read(&counter);
instead of
lazeyvalue = atomic_inc_return(&counter);
In fact I couldnt find one architecture where the later would be more expensive.
> Nick >
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