> From: Jane Chu <jane.chu@xxxxxxxxxx> > Subject: Re: [PATCH RESEND v6 1/9] pagemap: Introduce ->memory_failure() > > Sorry, correction in line. > > On 8/19/2021 12:18 AM, Jane Chu wrote: > > Hi, Shiyang, > > > > > > > 1) What does it take and cost to make > > > > > xfs_sb_version_hasrmapbt(&mp->m_sb) to return true? > > > > > > Enable rmpabt feature when making xfs filesystem > `mkfs.xfs > > -m rmapbt=1 /path/to/device` > BTW, reflink is enabled by default. > > > > Thanks! I tried > > mkfs.xfs -d agcount=2,extszinherit=512,su=2m,sw=1 -m reflink=0 -m > > rmapbt=1 -f /dev/pmem0 > > > > Again, injected a HW poison to the first page in a dax-file, had the > > poison consumed and received a SIGBUS. The result is better - > > > > ** SIGBUS(7): canjmp=1, whichstep=0, ** > > ** si_addr(0x0x7ff2d8800000), si_lsb(0x15), si_code(0x4, > > BUS_MCEERR_AR) ** > > > > The SIGBUS payload looks correct. > > > > However, "dmesg" has 2048 lines on sending SIGBUS, one per 512bytes - > > Actually that's one per 2MB, even though the poison is located in pfn 0x1850600 > only. > > > > > [ 7003.482326] Memory failure: 0x1850600: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7003.507956] > > Memory failure: 0x1850800: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7003.531681] > > Memory failure: 0x1850a00: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7003.554190] > > Memory failure: 0x1850c00: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7003.575831] > > Memory failure: 0x1850e00: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7003.596796] > > Memory failure: 0x1851000: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption .... > > [ 7045.738270] Memory failure: 0x194fe00: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7045.758885] > > Memory failure: 0x1950000: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7045.779495] > > Memory failure: 0x1950200: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption [ 7045.800106] > > Memory failure: 0x1950400: Sending SIGBUS to > > fsdax_poison_v1:4109 due to hardware memory corruption > > > > That's too much for a single process dealing with a single poison in a > > PMD page. If nothing else, given an .si_addr_lsb being 0x15, it > > doesn't make sense to send a SIGBUS per 512B block. > > > > Could you determine the user process' mapping size from the > > filesystem, and take that as a hint to determine how many iterations > > to call > > mf_dax_kill_procs() ? > > Sorry, scratch the 512byte stuff... the filesystem has been notified the length of > the poison blast radius, could it take clue from that? I think this is caused by a mistake I made in the 6th patch: xfs handler iterates the file range in block size(4k here) even though it is a PMD page. That's why so many message shows when poison on a PMD page. I'll fix it in next version. -- Thanks, Ruan. > > thanks, > -jane > > > > > thanks! > > -jane > > > > > >
