Date: Tue, 31 May 2011 22:21:42 +0200 From: Luigi Rizzo <rizzo@iet.unipi.it> To: current@freebsd.org Subject: "lazy" mmap for a device driver ? Message-ID: <20110531202142.GA7105@onelab2.iet.unipi.it>
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hi, i have a kernel module implementing a memory mapped special device which exports a large block of memory to the process. I see that when the process calls mmap(), my routine foo_mmap() is called immediately once per page, even though the process is not actually touching the pages. I believe this happens through dev_pager_alloc(). Right now i can live with that because all the memory is allocated at module load time, but i might want to have a sparse memory region which is populated dynamically, so i was wondering if there is a way to achieve this. I see there are two other device routines, d_mmap2 and d_mmap_single, any pointer to documentation or comments on how they differ ? thanks luigi
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