On 3/23/2022 1:58 PM, Michal Hocko wrote: > On Tue 22-03-22 17:24:58, Minchan Kim wrote: >> On Tue, Mar 22, 2022 at 02:46:48PM -0700, Andrew Morton wrote: >>> From: Charan Teja Kalla <quic_charante@xxxxxxxxxxx> >>> Subject: mm: madvise: skip unmapped vma holes passed to process_madvise >>> >>> The process_madvise() system call is expected to skip holes in vma passed >>> through 'struct iovec' vector list. But do_madvise, which >>> process_madvise() calls for each vma, returns ENOMEM in case of unmapped >>> holes, despite the VMA is processed. >>> >>> Thus process_madvise() should treat ENOMEM as expected and consider the >>> VMA passed to as processed and continue processing other vma's in the >>> vector list. Returning -ENOMEM to user, despite the VMA is processed, >>> will be unable to figure out where to start the next madvise. >>> >>> Link: https://lkml.kernel.org/r/4f091776142f2ebf7b94018146de72318474e686.1647008754.git.quic_charante@xxxxxxxxxxx >> I thought it was still under discussion and Charan will post next >> version along with previous patch >> "mm: madvise: return correct bytes advised with process_madvise" >> >> https://lore.kernel.org/linux-mm/7207b2f5-6b3e-aea4-aa1b-9c6d849abe34@xxxxxxxxxxx/ > Yes, I am not even sure the new semantic is sensible[1]. We should discuss > that and see all the consequences. Changing the semantic of an existing > syscall is always tricky going back and forth is even worse. Starting the discussion @ https://lore.kernel.org/linux-mm/cover.1648046642.git.quic_charante@xxxxxxxxxxx/ Thanks, Charan
