Hi, On 2021-05-29 12:03:12 +0100, Pavel Begunkov wrote: > On 5/29/21 1:33 AM, Andres Freund wrote: > > Hi, > > > > I started to see buffer registration randomly failing with ENOMEM on > > 5.13. Registering buffer or two often succeeds, but more than that > > rarely. Running the same program as root succeeds - but the user has a high > > rlimit. > > > > The issue is that io_sqe_buffer_register() doesn't initialize > > imu. io_buffer_account_pin() does imu->acct_pages++, before calling > > io_account_mem(ctx, imu->acct_pages); > > > > Which means that a random amount of memory is being accounted for. On the first > > few allocations this sometimes fails to fail because the memory is zero, but > > after a bit of reuse... > > Makes sense, thanks for digging in. I've just sent a patch, would > be great if you can test it or send your own. Sorry for the slow response, I'm off this week. I did just get around to test and unsurprisingly: The patch does fix the issue. Greetings, Andres Freund
