Messages in this thread | | | Subject | Re: [PATCH] fs: optimise generic_write_check_limits() | From | Pavel Begunkov <> | Date | Sat, 7 Aug 2021 11:05:38 +0100 |
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On 8/6/21 2:28 PM, Matthew Wilcox wrote: > On Fri, Aug 06, 2021 at 12:22:10PM +0100, Pavel Begunkov wrote: >> Even though ->s_maxbytes is used by generic_write_check_limits() only in >> case of O_LARGEFILE, the value is loaded unconditionally, which is heavy >> and takes 4 indirect loads. Optimise it by not touching ->s_maxbytes, >> if it's not going to be used. > > Is this "optimisation" actually worth anything? Look at how > force_o_largefile() is used. I would suggest that on the vast majority > of machines, O_LARGEFILE is always set.
Makes sense to leave it alone then, thanks
-- Pavel Begunkov
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