On 04/04/2013 06:39, Viacheslav Fedorov wrote: > Samuel Thibault <sthibault@debian.org <mailto:sthibault@debian.org>> writes: >>>when allocating an anonymous physical page on a Page Fault, >>> why does kernel have to fill it with zeroes? >>> I understand it has something to do with security. >>See man mmap. Anonymous memory is explicitly documented as being set to >>0. >>Samuel > > > Ok,thanks. So libraries and things are potentially expecting the memory to be 0, > hence my troubles. mmap(2) is documented to return 0-initialized pages for MAP_ANONYMOUS, so what are you fussing about? > By removing __GFP_ZERO flag from alloc_page_vma function. i.e. breaking documented behaviour. This is just like modifying the compiler to be non-conformant to standards, and complaining that standards-compliant programs fail as a result. -- Kind regards, Loong Jin
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