On Mon, Mar 18, 2024 at 2:03 PM Barry Song <21cnbao@xxxxxxxxx> wrote: > > On Tue, Mar 19, 2024 at 9:52 AM syzbot > <syzbot+adbc983a1588b7805de3@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > Hello, > > > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > > WARNING in __kmap_to_page > > > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 3529 at mm/highmem.c:167 __kmap_to_page+0x100/0x194 mm/highmem.c:167 > > Modules linked in: > > + Ira > > Hi Ira, > > I noticed this warning is coming from commit ef6e06b2ef87077. > > you have a commit message like > " Because it is intended to remove kmap_to_page() add a warn on once to > the kmap checks to flag potential issues early. > " > > Do we have a replacement for kmap_to_page()? The background is that we > want to pass a highmem buffer to sg_set_page() but we only know its virt > address. I am reviving this thread because new zsmalloc changes will make mappings sleepable, which will allow zswap to drop the memcpy() in zswap_decompress() -- except for the !virt_addr_valid() case. We can get rid of that too if we can use kmap_tp_page() in the scatterlist code. Ira, could you please answer Barry's question above about kmap_to_page()? It has been a year and kmap_to_page() is still around. Thanks.
