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charset=utf-8 Hey Qi, [=E2=80=A6] >=20 > Why not check pudval directly here? Like the following: >=20 > if (pud_leaf(*pud) || !pud_present(*pud)) > goto again; >=20 Good point, my initial idea [1] was also to put it there (although I checked on pud_special instead and continued instead of retrying). I wasn=E2=80=99t sure whether I could link to a thread in a patch = message, but there=E2=80=99s some discussion between David and me there. Making sure that a passed-in PMD range can be walked by checking=20 if the parent PUD is present & not a leaf feels better suited as a guard in the walk_pmd_range() function to me. After all, the failure = originates from inside that function, and potential other callers won=E2=80=99t = need to=20 incorporate the check which has to be done for safety anyways. It also makes the logic of walk_pud_range() more similar to=20 walk_pmd_range() - which also has the retry if it gets an ACTION_AGAIN from the walk_pte_range() call. Finally, doesn=E2=80=99t feel very natural to me to have: if (walk->vma) split_huge_pud(walk->vma, pud, addr); else if (pud_leaf(*pud) || !pud_present(*pud)) continue; /* Nothing to do. */ if (pud_leaf(*pud) || !pud_present(*pud)) goto again; /* Retry on concurrent refault as leaf */ [1] = https://lore.kernel.org/all/20260309174949.2514565-1-mboone@akamai.com/= --Apple-Mail=_971B1C9E-F167-4404-9055-FCFF4078040F Content-Disposition: attachment; filename="smime.p7s" Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCCcow ggShMIIESKADAgECAhMxAAAAIa0XYPGypwcKAAAAAAAhMAoGCCqGSM49BAMCMD8xITAfBgNVBAoT GEFrYW1haSBUZWNobm9sb2dpZXMgSW5jLjEaMBgGA1UEAxMRQWthbWFpQ29ycFJvb3QtRzEwHhcN MjQxMTIxMTgzNzUyWhcNMzQxMTIxMTg0NzUyWjA8MSEwHwYDVQQKExhBa2FtYWkgVGVjaG5vbG9n aWVzIEluYy4xFzAVBgNVBAMTDkFrYW1haUNsaWVudENBMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcD QgAEjkdeMHsSTytADJ7eJ+O+5mpBfm9hVC6Cg9Wf+ER8HXid3E68IHjcCTNFSiezqYclAnIalS1I cl6hRFZiacQkd6OCAyQwggMgMBIGCSsGAQQBgjcVAQQFAgMBAAEwIwYJKwYBBAGCNxUCBBYEFOa0 4dX2BYnqjkbEVEwLgf7BQJ7ZMB0GA1UdDgQWBBS2N+ieDVUAjPmykf1ahsljEXmtXDCBrwYDVR0g BIGnMIGkMIGhBgsqAwSPTgEJCQgBATCBkTBYBggrBgEFBQcCAjBMHkoAQQBrAGEAbQBhAGkAIABD AGUAcgB0AGkAZgBpAGMAYQB0AGUAIABQAHIAYQBjAHQAaQBjAGUAIABTAHQAYQB0AGUAbQBlAG4A dDA1BggrBgEFBQcCARYpaHR0cDovL2FrYW1haWNybC5ha2FtYWkuY29tL0FrYW1haUNQUy5wZGYw bAYDVR0lBGUwYwYIKwYBBQUHAwIGCCsGAQUFBwMEBgorBgEEAYI3FAICBgorBgEEAYI3CgMEBgor BgEEAYI3CgMMBggrBgEFBQcDBwYIKwYBBQUHAwkGCSsGAQQBgjcVBQYKKwYBBAGCNxQCATAZBgkr BgEEAYI3FAIEDB4KAFMAdQBiAEMAQTALBgNVHQ8EBAMCAYYwDwYDVR0TAQH/BAUwAwEB/zAfBgNV HSMEGDAWgBStAYfq3FmusRM5lU0PV6Akhot7vTCBgAYDVR0fBHkwdzB1oHOgcYYxaHR0cDovL2Fr YW1haWNybC5ha2FtYWkuY29tL0FrYW1haUNvcnBSb290LUcxLmNybIY8aHR0cDovL2FrYW1haWNy bC5kZncwMS5jb3JwLmFrYW1haS5jb20vQWthbWFpQ29ycFJvb3QtRzEuY3JsMIHIBggrBgEFBQcB AQSBuzCBuDA9BggrBgEFBQcwAoYxaHR0cDovL2FrYW1haWNybC5ha2FtYWkuY29tL0FrYW1haUNv cnBSb290LUcxLmNydDBIBggrBgEFBQcwAoY8aHR0cDovL2FrYW1haWNybC5kZncwMS5jb3JwLmFr YW1haS5jb20vQWthbWFpQ29ycFJvb3QtRzEuY3J0MC0GCCsGAQUFBzABhiFodHRwOi8vYWthbWFp b2NzcC5ha2FtYWkuY29tL29jc3AwCgYIKoZIzj0EAwIDRwAwRAIgaUoJ7eBk/qNcBVTJW5NC4NsO 6j4/6zQoKeKgOpeiXQUCIGkbSN83n1mMURZIK92KFRtn2X1nrZ7rcNuAQD5bvH1bMIIFITCCBMig AwIBAgITFwALOJfLRtbGzZc1dwABAAs4lzAKBggqhkjOPQQDAjA8MSEwHwYDVQQKExhBa2FtYWkg VGVjaG5vbG9naWVzIEluYy4xFzAVBgNVBAMTDkFrYW1haUNsaWVudENBMB4XDTI1MDgyODA3NTYy OVoXDTI3MDgyODA3NTYyOVowTjEZMBcGA1UECxMQTWFjQm9vayBQcm8tNDZZVDEPMA0GA1UEAxMG bWJvb25lMSAwHgYJKoZIhvcNAQkBFhFtYm9vbmVAYWthbWFpLmNvbTCCASIwDQYJKoZIhvcNAQEB BQADggEPADCCAQoCggEBAOX+npfSrX/rwhOySq6aejQMUVslPFpNvXdEnmMlnEjR95gq0Ygp+wQc Sde+JGBpGHsPMzHT1Nd3V1acm4cW1WB1aRqJOMfSLifg6SLkq2EM9WsftEiA1G4BT4UP0PFZY2Os 6TXvebAuVg6LwhB417rEJ2kuS/DKpiG8trAVDR6Uy9vbSMBp6iIewBc9r0CjW8l1zgRr+uQpXEUP mF2BV0l3Qo5r0nhPqTWR9oAX4/oTqnhbEhQ3tOFYTjzO1K9DdzX8mVggVSZz/M0v0gtkZVvO4B1t 3Sh+1lla5eMY4hlVHW1/FKqMe4EMXmDH7goTEuXPpelJiNRdBh7ud7xNNFUCAwEAAaOCAsowggLG MAsGA1UdDwQEAwIHgDApBgNVHSUEIjAgBggrBgEFBQcDAgYIKwYBBQUHAwQGCisGAQQBgjcKAwQw HQYDVR0OBBYEFO0y/xWMpkyOUMuNKmuzNtjXpdtRMEQGA1UdEQQ9MDugJgYKKwYBBAGCNxQCA6AY DBZtYm9vbmVAY29ycC5ha2FtYWkuY29tgRFtYm9vbmVAYWthbWFpLmNvbTAfBgNVHSMEGDAWgBS2 N+ieDVUAjPmykf1ahsljEXmtXDCBgAYDVR0fBHkwdzB1oHOgcYYxaHR0cDovL2FrYW1haWNybC5h a2FtYWkuY29tL0FrYW1haUNsaWVudENBKDEpLmNybIY8aHR0cDovL2FrYW1haWNybC5kZncwMS5j b3JwLmFrYW1haS5jb20vQWthbWFpQ2xpZW50Q0EoMSkuY3JsMIHIBggrBgEFBQcBAQSBuzCBuDA9 BggrBgEFBQcwAoYxaHR0cDovL2FrYW1haWNybC5ha2FtYWkuY29tL0FrYW1haUNsaWVudENBKDEp LmNydDBIBggrBgEFBQcwAoY8aHR0cDovL2FrYW1haWNybC5kZncwMS5jb3JwLmFrYW1haS5jb20v QWthbWFpQ2xpZW50Q0EoMSkuY3J0MC0GCCsGAQUFBzABhiFodHRwOi8vYWthbWFpb2NzcC5ha2Ft YWkuY29tL29jc3AwOwYJKwYBBAGCNxUHBC4wLAYkKwYBBAGCNxUIgs7lOoe41C2BhYsHouMhhtIP gUmFpcMQmtV/AgFkAgFTMDUGCSsGAQQBgjcVCgQoMCYwCgYIKwYBBQUHAwIwCgYIKwYBBQUHAwQw DAYKKwYBBAGCNwoDBDBEBgkqhkiG9w0BCQ8ENzA1MA4GCCqGSIb3DQMCAgIAgDAOBggqhkiG9w0D BAICAIAwBwYFKw4DAgcwCgYIKoZIhvcNAwcwCgYIKoZIzj0EAwIDRwAwRAIgD5UL4MI1RXeg64RR kifZAeItCnkZ4ecrqSEGpLcXV+ICIAdB9vZdM1WGxtag0rlqG0j0FBrCWixC0cdHNpFrqNx/MYIB 6TCCAeUCAQEwUzA8MSEwHwYDVQQKExhBa2FtYWkgVGVjaG5vbG9naWVzIEluYy4xFzAVBgNVBAMT DkFrYW1haUNsaWVudENBAhMXAAs4l8tG1sbNlzV3AAEACziXMA0GCWCGSAFlAwQCAQUAoGkwGAYJ KoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMjYwMzE4MDczNzMwWjAvBgkq hkiG9w0BCQQxIgQggRU2ccuUZPpQLWblikrjNiT3ZsGLWgFuBTfITu8APeMwDQYJKoZIhvcNAQEL BQAEggEAY/s+oiSxmPCjUUllHZcpIrG5BB0ucRQsmtcckzHO/lAnrSnSsE2+R516o7aalDLHHitG SxzA8CfsJbPLlpRVLaUdNX/6fzDKp3Sdpf8whd8wPwbU068fdXOyutPV4hIwv3R1qYgQeaUbdw0q o0f9+X/QtQMUCkh02LDBJA4BG6BVDBKz9r6uyONGBZug1Jmt3oqtEDVbrHAJTzR7oKkE3A0EWf5o V070fhcNpRm2vq6ys+GIXo5SyMrEM5H28WuIQCznXRMBRDezlyxPIgt2qAzP6o3wqLd0/52lXL0W ywPcGxS/sX/9YPeUdCbqJxfydeftUsaIIC75oXgdEX4nYgAAAAAAAA== --Apple-Mail=_971B1C9E-F167-4404-9055-FCFF4078040F--