Date: Sat, 4 Oct 2014 18:58:03 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: stable@freebsd.org, freebsd-current@freebsd.org Subject: Re: About pmap_mapdev() & pmap_unmapdev() Message-ID: <20141004155803.GQ26076@kib.kiev.ua> In-Reply-To: <20141004.205335.1782700760623869892.okuno.kohji@jp.panasonic.com> References: <20141004082943.GN26076@kib.kiev.ua> <20141004.175326.766405563100788209.okuno.kohji@jp.panasonic.com> <20141004092030.GP26076@kib.kiev.ua> <20141004.205335.1782700760623869892.okuno.kohji@jp.panasonic.com>
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On Sat, Oct 04, 2014 at 08:53:35PM +0900, Kohji Okuno wrote: > Hi Konstantin, > > Thank you for your prompt response. > I will test and report from next monday. > > >> In addtion, I have one question. > >> In current and 10-stable, is vm_map_delete() called by kva_free()? > > No, kva_free() only releases the vmem backing, leaving the page > > tables intact. This is why I only did the stable/9 patch. > > Where are PTEs allocated by pmap_mapdev() freed in current and 10-stable? > Could you please explain me? They are not freed. The removal of the vmem which covers the address space managed by corresponding ptes, allows the reuse of both KVA region and corresponding PTEs in the tables. The only concern with the resident page tables is to avoid two kva_alloc() to step over each other, and this is ensured by vmem.
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