On Sat, Jan 28, 2012 at 01:36:05PM +0100, K Macy wrote: > Il giorno 28/gen/2012, alle ore 09:39, Pawel Jakub Dawidek <p...@freebsd.org> > ha scritto: > > How do you handle the case when there are two small allocations within > > one page, where one has the NODUMP flag and one doesn't have the flag? > > Kmem_alloc and zone creation both work at granularities greater than or equal > to a page. The per-page management of dump is why this flag is not available > to generic malloc.
Hmm, kmem_alloc() in ZFS code is just a wrapper around generic malloc(9). You only added NODUMP flag for zio_data_buf_alloc(), but I think you can pass sizes smaller than eg. 4kB to that function (starting from SPA_MINBLOCKSIZE, which is 512 bytes). How can you tell some other ZFS code that uses kmem_alloc() won't share the same page as small ZIO buffer? I'd like to use that flag with GELI with generic malloc(9). How can I do that? Maybe defining this property at MALLOC_DEFINE() time for the entire malloc type would be better? I could then use two separate malloc types in GELI: one for sensitive data and one for other data. -- Pawel Jakub Dawidek http://www.wheelsystems.com FreeBSD committer http://www.FreeBSD.org Am I Evil? Yes, I Am! http://tupytaj.pl
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