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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?KGDHmm2F4MCX0ShkZ3CW8nal0iR6jEsI21OKSWn1kc+48Z+R20PGmLkGT02a?= =?us-ascii?Q?JEMebL5yRF+ML3M/Jm61a8FQ9UPz/Eh9hYhs5FloNT6ZZOyhlUPYLekxkifD?= =?us-ascii?Q?0M3UgUTXtg1qjPXC8AJKlqdvpvH6gKRsw66GXaoJAkkr1wK0QyzFPcTgvVr4?= =?us-ascii?Q?46V4sUdzeUlDrop3TPPRTfr9KYVvgKKdffsKSDlIQFBG5ClOMK0kBdMYZeBc?= =?us-ascii?Q?f7s7GMkS/k0i46lviWNIrSK5pgZUPl41h2/2bXM/7FFAZgOZPh61YK3k3qsm?= =?us-ascii?Q?cdTxE4x73zrB6Q1y+zuFItunA74XnvMIErlixwi7lrqjZydYcqbKQ2apcomv?= =?us-ascii?Q?IHP8ZJjAT199+hWlLqmqJLpk0E/kbU4Ce7reAPUFFRDQNm7K7F72RqwOIiyW?= =?us-ascii?Q?7yz6jGruH3g/Ipl8RQtzA1fA6hbTIeG7a5Wnc/Zrlip7bziBhOLvMry3G10j?= =?us-ascii?Q?WvllzUM93B0zXw5tA/PoPXOHPsiHRmbe4WemZw66Cfi6DEFkk9nbrHC0UdnZ?= =?us-ascii?Q?+cQXA3wJbBPn0ehCIYVff1/Ev/63sr8gFXuS2NwP1R4OQoGSwoKAAokKvbwr?= =?us-ascii?Q?moJW2JI7SNeoexLdR/bgnUkME0fnhNHnZmsRAH/gbGBaogTCRHXGOH6X+JUT?= =?us-ascii?Q?edW0F71F4IAKyn3sGM64AxQ9Ok2v2DxJF2BSIJR9CBY+3RrpqtIeoA7CeI7H?= =?us-ascii?Q?P+8Ssdj97yALFrK3h1jFIJGBPS1AXUkBGgIaH6udySCZQGQ7HUFsN2naMWpg?= =?us-ascii?Q?3NO22w8nZ69UAGoSH34vp+axZJOz22XFxn8Jbtx3jV9Pnwk3QUBlTLJBKbUw?= =?us-ascii?Q?JZuoGO0cQXseJA4sa5S8nmGQsEW3RJFGM8qXILBrPGMcl4HcVbHjoce1uIGR?= =?us-ascii?Q?xXcYhN0Ajh+jI64zbk2m1OY8T274Qeq66kWXVPqswg8oPtVNdyvSOTiQHNuc?= =?us-ascii?Q?1OMV3mQjPAavgOB0qw82EaSNxLjv1aQ4xuy7bce+4b3dEIOPS0gfW7Ph9uIX?= =?us-ascii?Q?Oklz2cdJ1N40nQtzyLfqDIE+f94vO1Xs5mAjKW6xjt4KYT0LyBZaWSVY1tOW?= =?us-ascii?Q?B+tVP7HP+cuA/29jSBnlC4ANDq7Ov4aZCHJp+yKP5dK1pCmjkVbsJCdfvPIV?= =?us-ascii?Q?HoXOl2nE54QMvwl/CwTjprBrLO7LrTLFlGrVZ+eAusyFuamNORg3fWilT+w7?= =?us-ascii?Q?M4mEqWHyJ1d4D0IxkcWlYqa6VDw4yyC3xnKwQ723p05dto5kb3RsZX+lUcum?= =?us-ascii?Q?uilLEcfIiL1q/2MXBPyNBzhOEd2OzwSeV2b3g8xK50XBq3i650MILxYp8NWz?= =?us-ascii?Q?69y0mLq+DvmMH6cCL/3BbAFve2mqIdtkTxkzNxDxUlsRXEwDPIVJdB2vDTF6?= =?us-ascii?Q?faq1NJkl10vZrmJSsl/Q7CrDmZL2LqFU9a/Cw+gIHZeIDCqanH4ATCXuUoyV?= =?us-ascii?Q?ks4ac0If5Jeg5EkL3kdrg9NzL11jXE4UuxdG6LH9O1XbK7G8sU/74WYj9/ow?= =?us-ascii?Q?ODiJyZ2x+VfWSofNZM9Zkcbcgxk6ogFUAlLobvjQJBkZM0+wSeiEr1KcCuDJ?= =?us-ascii?Q?7wiTxaMoR/dVlv4VbuZt3048G1O7ueJR7i/7a61r?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 92e0ab3a-6fa0-4592-d28a-08de12587fda X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Oct 2025 17:20:44.8349 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 6qWaovXQadnmmJK5NIsdO5EqZzyKICaZK0jK+cnDWM+lNs1bc6GrVeZuLpvmB0YY X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB6924 On 23 Oct 2025, at 7:10, Pankaj Raghav wrote: > On 10/23/25 05:05, Zi Yan wrote: >> folio split clears PG_has_hwpoisoned, but the flag should be preserved in >> after-split folios containing pages with PG_hwpoisoned flag if the folio is >> split to >0 order folios. Scan all pages in a to-be-split folio to >> determine which after-split folios need the flag. >> >> An alternatives is to change PG_has_hwpoisoned to PG_maybe_hwpoisoned to >> avoid the scan and set it on all after-split folios, but resulting false >> positive has undesirable negative impact. To remove false positive, caller >> of folio_test_has_hwpoisoned() and folio_contain_hwpoisoned_page() needs to >> do the scan. That might be causing a hassle for current and future callers >> and more costly than doing the scan in the split code. More details are >> discussed in [1]. >> >> This issue can be exposed via: >> 1. splitting a has_hwpoisoned folio to >0 order from debugfs interface; > > Is it easy to add a selftest in split_huge_page_test for this scenario? Probably, but I prefer to do this in a separate memory failure test. I think the steps are: 0. set up a SIGBUS handler, 1. get a XFS image, like split_huge_page_test does, 2. set block size > page size, 3. fault in a large folio bigger than block size, 4. madvise(MADV_HWPOISON), 5. catch SIGBUS since the folio cannot be split to order-0 and check the corresponding folio's has_hwpoison flag. I will put this on my TODO list. > >> 2. truncating part of a has_hwpoisoned folio in >> truncate_inode_partial_folio(). >> > -- > Pankaj -- Best Regards, Yan, Zi