Messages in this thread | | | Date | Fri, 15 Jun 2018 21:27:26 +0200 | From | Thomas Petazzoni <> | Subject | Re: [PATCH] arch/sh: use slow path for get_user_pages_fast() on SMP |
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Hello,
On Fri, 15 Jun 2018 19:04:45 +0300, Sergei Shtylyov wrote: > Hello! > > On 06/15/2018 06:52 PM, Thomas Petazzoni wrote: > > > The fast path of get_user_pages_fast() disables IRQs and then does: > > > > - gup_pud_range() > > - gup_pmd_range() > > - gup_pte_range() > > - flush_dcache_page() > > > > However, flush_dcache_page() makes a smp_call_function(), and using > > smp_call_function() when IRQs are disabled is not allowed. > > > > In order to work around this problem, this commit prevents the fast > > path from get_user_pages_fast() from being used on SMP, and directly > ^^^^ of? > Else it sounds a bit tautological...
I re-read again my sentence, and I believe it's correct and it has the meaning I intended to give. Of course, I'm not a native english speaker, so I might be wrong on this :-)
I'm actually more interested in hearing whether there is a better solution to this problem. This patch submission is really a very proposal, and I'm hoping to get some better suggestions on how to approach the problem.
Best regards,
Thomas -- Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com
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