On 12/21/2018 11:58 AM, Konstantin Khorenko wrote: > Hi Bartlomiej, > > On 12/20/2018 07:21 PM, Bartlomiej Zolnierkiewicz wrote: >> On 11/26/2018 11:02 AM, Konstantin Khorenko wrote: >>> Scrollback frame buffer is rather big - 32K, >>> so it requires 3rd order page, so let's use kvmalloc() instead of >>> ordinary kmalloc() for it. >> >> Is it actually safe to use non-contiguous memory for softback_buf? > > Well, that's why we need a review. :) :) > i've asked myself same question while fixing this, > i've dig sources a bit and did not find places when softback_buf is provided for DMA, > all other places seems to work with virtual addresses, so there should be no problem. > > Even more i saw a function which mentions that softback might be non-contigious: > > /* As we might be inside of softback, we may work with non-contiguous buffer, > that's why we have to use a separate routine. */ > static void fbcon_invert_region(struct vc_data *vc, u16 * p, int cnt) > > So i think it's safe to use kvmalloc() here. Patch queued for v5.1, thanks. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics