Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
To:     Hans de Goede <hdegoede@redhat.com>, Tejun Heo <tj@kernel.org>
Cc:     linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
From:   Paul Menzel <pmenzel+linux-ide@molgen.mpg.de>
Subject: Decrease boot time with AHCI drives?
Message-ID: <b0843e21-3e8d-0c00-b69b-16567dd3ee2a@molgen.mpg.de>
Date:   Wed, 4 Apr 2018 11:53:06 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.7.0
MIME-Version: 1.0
Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="------------ms070107060607000702070608"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This is a cryptographically signed message in MIME format.

--------------ms070107060607000702070608
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: quoted-printable

Dear Linux folks,


I am trying to decrease the boot time of the Linux kernel so the LUKS=20
passphrase dialog (in the initrd) is shown as quickly as possible. The=20
devices I test with is a Lenovo X60 and ASRock E350M1 both running with=20
coreboot and the GRUB payload. The goal is to do this without having to=20
rebuild a Linux kernel, but only by run-time

I am currently at 1.2 seconds.

```
[    0.610437] calling  ata_init+0x0/0x2be [libata] @ 88
[    0.610548] libata version 3.00 loaded.
[    0.610570] initcall ata_init+0x0/0x2be [libata] returned 0 after 107 =

usecs
[    0.612100] calling  serio_raw_drv_init+0x0/0x1000 [serio_raw] @ 89
[    0.612132] initcall serio_raw_drv_init+0x0/0x1000 [serio_raw]=20
returned 0 after 25 usecs
[    0.612659] calling  ahci_pci_driver_init+0x0/0x1000 [ahci] @ 88
[    0.612715] ahci 0000:00:1f.2: version 3.0
[    0.613050] ahci 0000:00:1f.2: SSS flag set, parallel bus scan disable=
d
[    0.613153] ahci 0000:00:1f.2: AHCI 0001.0100 32 slots 4 ports 1.5=20
Gbps 0x1 impl SATA mode
[    0.613239] ahci 0000:00:1f.2: flags: 64bit ncq ilck stag pm led clo=20
pmp pio slum part
[    0.613915] calling  evdev_init+0x0/0x1000 [evdev] @ 85
[    0.614178] initcall evdev_init+0x0/0x1000 [evdev] returned 0 after=20
250 usecs
[    0.624366] scsi host0: ahci
[    0.630638] scsi host1: ahci
[    0.640413] scsi host2: ahci
[    0.646559] scsi host3: ahci
[    0.646752] ata1: SATA max UDMA/133 abar m1024@0xe4445000 port=20
0xe4445100 irq 28
[    0.646836] ata2: DUMMY
[    0.646902] ata3: DUMMY
[    0.646964] ata4: DUMMY
[    0.647098] initcall ahci_pci_driver_init+0x0/0x1000 [ahci] returned=20
0 after 33619 usecs
[    1.124129] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[    1.124605] ata1.00: ATA-9: M4-CT256M4SSD2, 070H, max UDMA/100
[    1.124674] ata1.00: 500118192 sectors, multi 16: LBA48 NCQ (depth=20
31/32), AA
[    1.125179] ata1.00: configured for UDMA/100
[    1.125522] scsi 0:0:0:0: Direct-Access     ATA      M4-CT256M4SSD2=20
070H PQ: 0 ANSI: 5
[    1.129127] calling  init_sd+0x0/0x1000 [sd_mod] @ 84
[    1.129268] initcall init_sd+0x0/0x1000 [sd_mod] returned 0 after 129 =

usecs
[    1.129444] sd 0:0:0:0: [sda] 500118192 512-byte logical blocks: (256 =

GB/238 GiB)
[    1.129550] sd 0:0:0:0: [sda] Write Protect is off
[    1.129619] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[    1.129647] sd 0:0:0:0: [sda] Write cache: enabled, read cache:=20
enabled, doesn't support DPO or FUA
[    1.130384]  sda: sda1 sda2
[    1.131009] sd 0:0:0:0: [sda] Attached SCSI disk
[    1.213492] calling  dm_init+0x0/0x31 [dm_mod] @ 110
[    1.213535] device-mapper: uevent: version 1.0.3
[    1.213727] device-mapper: ioctl: 4.37.0-ioctl (2017-09-20)=20
initialised: dm-devel@redhat.com
[    1.213829] initcall dm_init+0x0/0x31 [dm_mod] returned 0 after 312 us=
ecs
[    1.214434] calling  dm_crypt_init+0x0/0x1000 [dm_crypt] @ 110
[    1.214442] initcall dm_crypt_init+0x0/0x1000 [dm_crypt] returned 0=20
after 2 usecs
```

So, according to `initcall_debug` the method `ahci_pci_driver_init`=20
takes 33 ms to execute, which is longer then a few milliseconds.

But more importantly, it takes roughly half a second to set up the=20
device. I understand, that the probing is part of AHCI(?), and in this=20
case the Crucial m4 SSD drive/firmware is especially slow. So, I assume=20
it will be hard to improve anything in the code to decrease the time.

That said, in my case the assumption is, that the device configuration=20
will not change. That means, the drive will be the same and will be=20
connected to the same port all the time.

Additionally, GRUB already probed the device to read the Linux kernel=20
image and initrd image.

So, is there a way to avoid doing the probing twice or at all? That=20
means, either cache the settings, and load them during boot by reading=20
it from the firmware flash ROM chip, possible when using coreboot, and=20
passing it to the Linux kernel for example by GRUB. That would also help =

with LinuxBoot [1], where the Linux kernel is used as the payload (boot=20
kernel), already setting up the drive and kexec=E2=80=99s another Linux k=
ernel,=20
read from the drive.

Or, GRUB passes the settings it detected to the Linux kernel.


Kind regards,

Paul


[1] https://www.linuxboot.org/


--------------ms070107060607000702070608
Content-Type: application/pkcs7-signature; name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7s"
Content-Description: S/MIME Cryptographic Signature

MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCC
EFowggUSMIID+qADAgECAgkA4wvV+K8l2YEwDQYJKoZIhvcNAQELBQAwgYIxCzAJBgNVBAYT
AkRFMSswKQYDVQQKDCJULVN5c3RlbXMgRW50ZXJwcmlzZSBTZXJ2aWNlcyBHbWJIMR8wHQYD
VQQLDBZULVN5c3RlbXMgVHJ1c3QgQ2VudGVyMSUwIwYDVQQDDBxULVRlbGVTZWMgR2xvYmFs
Um9vdCBDbGFzcyAyMB4XDTE2MDIyMjEzMzgyMloXDTMxMDIyMjIzNTk1OVowgZUxCzAJBgNV
BAYTAkRFMUUwQwYDVQQKEzxWZXJlaW4genVyIEZvZXJkZXJ1bmcgZWluZXMgRGV1dHNjaGVu
IEZvcnNjaHVuZ3NuZXR6ZXMgZS4gVi4xEDAOBgNVBAsTB0RGTi1QS0kxLTArBgNVBAMTJERG
Ti1WZXJlaW4gQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkgMjCCASIwDQYJKoZIhvcNAQEBBQAD
ggEPADCCAQoCggEBAMtg1/9moUHN0vqHl4pzq5lN6mc5WqFggEcVToyVsuXPztNXS43O+FZs
FVV2B+pG/cgDRWM+cNSrVICxI5y+NyipCf8FXRgPxJiZN7Mg9mZ4F4fCnQ7MSjLnFp2uDo0p
eQcAIFTcFV9Kltd4tjTTwXS1nem/wHdN6r1ZB+BaL2w8pQDcNb1lDY9/Mm3yWmpLYgHurDg0
WUU2SQXaeMpqbVvAgWsRzNI8qIv4cRrKO+KA3Ra0Z3qLNupOkSk9s1FcragMvp0049ENF4N1
xDkesJQLEvHVaY4l9Lg9K7/AjsMeO6W/VRCrKq4Xl14zzsjz9AkH4wKGMUZrAcUQDBHHWekC
AwEAAaOCAXQwggFwMA4GA1UdDwEB/wQEAwIBBjAdBgNVHQ4EFgQUk+PYMiba1fFKpZFK4OpL
4qIMz+EwHwYDVR0jBBgwFoAUv1kgNgB5oKAia4zV8mHSuCzLgkowEgYDVR0TAQH/BAgwBgEB
/wIBAjAzBgNVHSAELDAqMA8GDSsGAQQBga0hgiwBAQQwDQYLKwYBBAGBrSGCLB4wCAYGZ4EM
AQICMEwGA1UdHwRFMEMwQaA/oD2GO2h0dHA6Ly9wa2kwMzM2LnRlbGVzZWMuZGUvcmwvVGVs
ZVNlY19HbG9iYWxSb290X0NsYXNzXzIuY3JsMIGGBggrBgEFBQcBAQR6MHgwLAYIKwYBBQUH
MAGGIGh0dHA6Ly9vY3NwMDMzNi50ZWxlc2VjLmRlL29jc3ByMEgGCCsGAQUFBzAChjxodHRw
Oi8vcGtpMDMzNi50ZWxlc2VjLmRlL2NydC9UZWxlU2VjX0dsb2JhbFJvb3RfQ2xhc3NfMi5j
ZXIwDQYJKoZIhvcNAQELBQADggEBAIcL/z4Cm2XIVi3WO5qYi3FP2ropqiH5Ri71sqQPrhE4
eTizDnS6dl2e6BiClmLbTDPo3flq3zK9LExHYFV/53RrtCyD2HlrtrdNUAtmB7Xts5et6u5/
MOaZ/SLick0+hFvu+c+Z6n/XUjkurJgARH5pO7917tALOxrN5fcPImxHhPalR6D90Bo0fa3S
PXez7vTXTf/D6OWST1k+kEcQSrCFWMBvf/iu7QhCnh7U3xQuTY+8npTD5+32GPg8SecmqKc2
2CzeIs2LgtjZeOJVEqM7h0S2EQvVDFKvaYwPBt/QolOLV5h7z/0HJPT8vcP9SpIClxvyt7bP
ZYoaorVyGTkwggWNMIIEdaADAgECAgwcOtRQhH7u81j4jncwDQYJKoZIhvcNAQELBQAwgZUx
CzAJBgNVBAYTAkRFMUUwQwYDVQQKEzxWZXJlaW4genVyIEZvZXJkZXJ1bmcgZWluZXMgRGV1
dHNjaGVuIEZvcnNjaHVuZ3NuZXR6ZXMgZS4gVi4xEDAOBgNVBAsTB0RGTi1QS0kxLTArBgNV
BAMTJERGTi1WZXJlaW4gQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkgMjAeFw0xNjExMDMxNTI0
NDhaFw0zMTAyMjIyMzU5NTlaMGoxCzAJBgNVBAYTAkRFMQ8wDQYDVQQIDAZCYXllcm4xETAP
BgNVBAcMCE11ZW5jaGVuMSAwHgYDVQQKDBdNYXgtUGxhbmNrLUdlc2VsbHNjaGFmdDEVMBMG
A1UEAwwMTVBHIENBIC0gRzAyMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnhx4
59Lh4WqgOs/Md04XxU2yFtfM15ZuJV0PZP7BmqSJKLLPyqmOrADfNdJ5PIGBto2JBhtRRBHd
G0GROOvTRHjzOga95WOTeura79T21FWwwAwa29OFnD3ZplQs6HgdwQrZWNi1WHNJxn/4mA19
rNEBUc5urSIpZPvZi5XmlF3v3JHOlx3KWV7mUteB4pwEEfGTg4npPAJbp2o7arxQdoIq+Pu2
OsvqhD7Rk4QeaX+EM1QS4lqd1otW4hE70h/ODPy1xffgbZiuotWQLC6nIwa65Qv6byqlIX0q
Zuu99Vsu+r3sWYsL5SBkgecNI7fMJ5tfHrjoxfrKl/ErTAt8GQIDAQABo4ICBTCCAgEwEgYD
VR0TAQH/BAgwBgEB/wIBATAOBgNVHQ8BAf8EBAMCAQYwKQYDVR0gBCIwIDANBgsrBgEEAYGt
IYIsHjAPBg0rBgEEAYGtIYIsAQEEMB0GA1UdDgQWBBTEiKUH7rh7qgwTv9opdGNSG0lwFjAf
BgNVHSMEGDAWgBST49gyJtrV8UqlkUrg6kviogzP4TCBjwYDVR0fBIGHMIGEMECgPqA8hjpo
dHRwOi8vY2RwMS5wY2EuZGZuLmRlL2dsb2JhbC1yb290LWcyLWNhL3B1Yi9jcmwvY2Fjcmwu
Y3JsMECgPqA8hjpodHRwOi8vY2RwMi5wY2EuZGZuLmRlL2dsb2JhbC1yb290LWcyLWNhL3B1
Yi9jcmwvY2FjcmwuY3JsMIHdBggrBgEFBQcBAQSB0DCBzTAzBggrBgEFBQcwAYYnaHR0cDov
L29jc3AucGNhLmRmbi5kZS9PQ1NQLVNlcnZlci9PQ1NQMEoGCCsGAQUFBzAChj5odHRwOi8v
Y2RwMS5wY2EuZGZuLmRlL2dsb2JhbC1yb290LWcyLWNhL3B1Yi9jYWNlcnQvY2FjZXJ0LmNy
dDBKBggrBgEFBQcwAoY+aHR0cDovL2NkcDIucGNhLmRmbi5kZS9nbG9iYWwtcm9vdC1nMi1j
YS9wdWIvY2FjZXJ0L2NhY2VydC5jcnQwDQYJKoZIhvcNAQELBQADggEBABLpeD5FygzqOjj+
/lAOy20UQOGWlx0RMuPcI4nuyFT8SGmK9lD7QCg/HoaJlfU/r78ex+SEide326evlFAoJXIF
jVyzNltDhpMKrPIDuh2N12zyn1EtagqPL6hu4pVRzcBpl/F2HCvtmMx5K4WN1L1fmHWLcSap
dhXLvAZ9RG/B3rqyULLSNN8xHXYXpmtvG0VGJAndZ+lj+BH7uvd3nHWnXEHC2q7iQlDUqg0a
wIqWJgdLlx1Q8Dg/sodv0m+LN0kOzGvVDRCmowBdWGhhusD+duKV66pBl+qhC+4LipariWaM
qK5ppMQROATjYeNRvwI+nDcEXr2vDaKmdbxgDVwwggWvMIIEl6ADAgECAgweKlJIhfynPMVG
/KIwDQYJKoZIhvcNAQELBQAwajELMAkGA1UEBhMCREUxDzANBgNVBAgMBkJheWVybjERMA8G
A1UEBwwITXVlbmNoZW4xIDAeBgNVBAoMF01heC1QbGFuY2stR2VzZWxsc2NoYWZ0MRUwEwYD
VQQDDAxNUEcgQ0EgLSBHMDIwHhcNMTcxMTE0MTEzNDE2WhcNMjAxMTEzMTEzNDE2WjCBizEL
MAkGA1UEBhMCREUxIDAeBgNVBAoMF01heC1QbGFuY2stR2VzZWxsc2NoYWZ0MTQwMgYDVQQL
DCtNYXgtUGxhbmNrLUluc3RpdHV0IGZ1ZXIgbW9sZWt1bGFyZSBHZW5ldGlrMQ4wDAYDVQQL
DAVNUElNRzEUMBIGA1UEAwwLUGF1bCBNZW56ZWwwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAw
ggEKAoIBAQDIh/UR/AX/YQ48VWWDMLTYtXjYJyhRHMc81ZHMMoaoG66lWB9MtKRTnB5lovLZ
enTIUyPsCrMhTqV9CWzDf6v9gOTWVxHEYqrUwK5H1gx4XoK81nfV8oGV4EKuVmmikTXiztGz
peyDmOY8o/EFNWP7YuRkY/lPQJQBeBHYq9AYIgX4StuXu83nusq4MDydygVOeZC15ts0tv3/
6WmibmZd1OZRqxDOkoBbY3Djx6lERohs3IKS6RKiI7e90rCSy9rtidJBOvaQS9wvtOSKPx0a
+2pAgJEVzZFjOAfBcXydXtqXhcpOi2VCyl+7+LnnTz016JJLsCBuWEcB3kP9nJYNAgMBAAGj
ggIxMIICLTAJBgNVHRMEAjAAMA4GA1UdDwEB/wQEAwIF4DAdBgNVHSUEFjAUBggrBgEFBQcD
AgYIKwYBBQUHAwQwHQYDVR0OBBYEFHM0Mc3XjMLlhWpp4JufRELL4A/qMB8GA1UdIwQYMBaA
FMSIpQfuuHuqDBO/2il0Y1IbSXAWMCAGA1UdEQQZMBeBFXBtZW56ZWxAbW9sZ2VuLm1wZy5k
ZTB9BgNVHR8EdjB0MDigNqA0hjJodHRwOi8vY2RwMS5wY2EuZGZuLmRlL21wZy1nMi1jYS9w
dWIvY3JsL2NhY3JsLmNybDA4oDagNIYyaHR0cDovL2NkcDIucGNhLmRmbi5kZS9tcGctZzIt
Y2EvcHViL2NybC9jYWNybC5jcmwwgc0GCCsGAQUFBwEBBIHAMIG9MDMGCCsGAQUFBzABhido
dHRwOi8vb2NzcC5wY2EuZGZuLmRlL09DU1AtU2VydmVyL09DU1AwQgYIKwYBBQUHMAKGNmh0
dHA6Ly9jZHAxLnBjYS5kZm4uZGUvbXBnLWcyLWNhL3B1Yi9jYWNlcnQvY2FjZXJ0LmNydDBC
BggrBgEFBQcwAoY2aHR0cDovL2NkcDIucGNhLmRmbi5kZS9tcGctZzItY2EvcHViL2NhY2Vy
dC9jYWNlcnQuY3J0MEAGA1UdIAQ5MDcwDwYNKwYBBAGBrSGCLAEBBDARBg8rBgEEAYGtIYIs
AQEEAwYwEQYPKwYBBAGBrSGCLAIBBAMGMA0GCSqGSIb3DQEBCwUAA4IBAQCQs6bUDROpFO2F
Qz2FMgrdb39VEo8P3DhmpqkaIMC5ZurGbbAL/tAR6lpe4af682nEOJ7VW86ilsIJgm1j0ueY
aOuL8jrN4X7IF/8KdZnnNnImW3QVni6TCcc+7+ggci9JHtt0IDCj5vPJBpP/dKXLCN4M+exl
GXYpfHgxh8gclJPY1rquhQrihCzHfKB01w9h9tWZDVMtSoy9EUJFhCXw7mYUsvBeJwZesN2B
fndPkrXx6XWDdU3S1LyKgHlLIFtarLFm2Hb5zAUR33h+26cN6ohcGqGEEzgIG8tXS8gztEaj
1s2RyzmKd4SXTkKR3GhkZNVWy+gM68J7jP6zzN+cMYIDmjCCA5YCAQEwejBqMQswCQYDVQQG
EwJERTEPMA0GA1UECAwGQmF5ZXJuMREwDwYDVQQHDAhNdWVuY2hlbjEgMB4GA1UECgwXTWF4
LVBsYW5jay1HZXNlbGxzY2hhZnQxFTATBgNVBAMMDE1QRyBDQSAtIEcwMgIMHipSSIX8pzzF
RvyiMA0GCWCGSAFlAwQCAQUAoIIB8TAYBgkqhkiG9w0BCQMxCwYJKoZIhvcNAQcBMBwGCSqG
SIb3DQEJBTEPFw0xODA0MDQwOTUzMDZaMC8GCSqGSIb3DQEJBDEiBCDqbjrbS8mWLnVSwo46
oeOoBqC6Hk0Xi0WYeVNImorFlzBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjALBglg
hkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFAMAcG
BSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGJBgkrBgEEAYI3EAQxfDB6MGoxCzAJBgNVBAYTAkRF
MQ8wDQYDVQQIDAZCYXllcm4xETAPBgNVBAcMCE11ZW5jaGVuMSAwHgYDVQQKDBdNYXgtUGxh
bmNrLUdlc2VsbHNjaGFmdDEVMBMGA1UEAwwMTVBHIENBIC0gRzAyAgweKlJIhfynPMVG/KIw
gYsGCyqGSIb3DQEJEAILMXygejBqMQswCQYDVQQGEwJERTEPMA0GA1UECAwGQmF5ZXJuMREw
DwYDVQQHDAhNdWVuY2hlbjEgMB4GA1UECgwXTWF4LVBsYW5jay1HZXNlbGxzY2hhZnQxFTAT
BgNVBAMMDE1QRyBDQSAtIEcwMgIMHipSSIX8pzzFRvyiMA0GCSqGSIb3DQEBAQUABIIBAI91
194T3oJ4dkOoSrF/eIW0YUotWwC+V6C2tj/9O2ZgM6rlMT57iFhB9SxmNl3HYmGfyIJf7sWn
OpZTN9AbccYPGhlC0/am48dehqe+ImwjW0eo618l1drUA1i4fNf5E43MjLIVZATUwcPRWQUE
kWpceQCYIrm3S/AcUVV21VRIpyfrz0HE1cPw4Wtdw68PcGaeuVXzpU26rOUD2jR9oCdBipF0
g+UBayY1JvD6YHXuWbEiC+xYvJE3E0k4Smk98skXCCSyFGAKF8Oe2xpo9NgAG0tZB0r6hHty
d2Sy0xoVbXjCj0kvzSkKRBVJ68ldzPdtm7iBqw9xC2f0N6iKLmUAAAAAAAA=
--------------ms070107060607000702070608--