Messages in this thread | | | Date | Sat, 14 Mar 2015 23:02:43 +0100 | Subject | Re: [PATCH 4/8] fbdev: ssd1307fb: Use vmalloc to allocate video memory. | From | Geert Uytterhoeven <> |
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On Fri, Mar 13, 2015 at 10:31 PM, Thomas Niederprüm <niederp@physik.uni-kl.de> wrote: > Am Tue, 10 Mar 2015 13:28:25 +0200 > schrieb Tomi Valkeinen <tomi.valkeinen@ti.com>: >> Also, isn't doing __pa() for the memory returned by vmalloc plain >> wrong? > >> What was the crash about when using kmalloc? It would be good to fix >> defio, as I don't see why it should not work with kmalloced memory. > > The main challenge here is that the memory handed to userspace upon > mmap call needs to be page aligned. The memory returned by kmalloc has > no such alignment, but the pointer presented to the userspace program > gets aligned to next page boundary. It's not clear to me whether there > is an easy way to obtain page aligned kmalloc memory. Memory > allocated by vmalloc on the other hand is always aligned to page > boundaries. This is why I chose to go for vmalloc.
__get_free_pages()?
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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