Messages in this thread | | | Date | Tue, 18 Apr 2017 08:28:17 -0500 (CDT) | From | Christoph Lameter <> | Subject | Re: copy_page() on a kmalloc-ed page with DEBUG_SLAB enabled (was "zram: do not use copy_page with non-page alinged address") |
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On Tue, 18 Apr 2017, Sergey Senozhatsky wrote:
> > Simple solution is to not allocate pages via the slab allocator but use > > the page allocator for this. The page allocator provides proper alignment. > > sure, but at the same time it's not completely uncommon and unseen thing > > ~/_next$ git grep kmalloc | grep PAGE_SIZE | wc -l > 75
Of course if you want a PAGE_SIZE object that is not really page aligned etc then its definitely ok to use.
> not all, if any, of those pages get into copy_page(), of course. may be... hopefully. > so may be a warning would make sense and save time some day. but up to MM > people to decide.
Slab objects are copied using memcpy. copy_page is for pages aligned to page boundaries and the arch code there may have additional expectations that cannot be met by the slab allocators.
> p.s. Christoph, FYI, gmail automatically marked your message > as a spam message, for some reason.
Weird. Any more details as to why?
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