Messages in this thread Patch in this message | | | Subject | [PATCH] sata_nv: add a module parameter to enable async scanning | From | Andreas Robinson <> | Date | Sun, 08 Mar 2009 21:13:57 +0100 |
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On Sun, 2009-03-08 at 09:01 -0700, Arjan van de Ven wrote: > One thing to mention is that fastinit for sata... I only did AHCI > (because all my machines have that). Your machine looks like it has > something different than AHCI, so maybe the sata controller can use > some work ;-) > (a sata driver needs to opt into parallel scanning via a flag) > > SATA init tends to be one of the things that are fix time per drive; > and so working on that first to at least ONLY get that is worth it, > it's a huge chunk of time (more than half the total time in your > bootchart)
Something like the patch below, mabye? :-)
Before: [ 3.056308] Freeing unused kernel memory: 364k freed After: [ 2.411417] Freeing unused kernel memory: 364k freed
The chipset is nforce2 (drivers/ata/sata_nv.c). I couldn't find anything like the SSS flag documented in the code, and register specs from nvidia are as rare as hen's teeth... So I only added the module parameter to force parallel scans.
I named it parallel_scan instead of ignore_sss though, since there might not be an SSS-flag to ignore.
/Andreas
>From a5b090856173782308c8f61de84085be9a9b73ba Mon Sep 17 00:00:00 2001 From: Andreas Robinson <andr345@gmail.com> Date: Sun, 8 Mar 2009 20:44:16 +0100 Subject: [PATCH] sata_nv: add a module parameter to enable async scanning
This parameter (parallel_scan) forces the OS to scan for disks asynchronously/in parallel, to reduce boot time.
It might cause problems (brown-outs, blown fuses) in multi-drive systems, if the PSU is unable to handle several drives spinning up simultaneously.
It ought to be safe in single-drive systems.
Signed-off-by: Andreas Robinson <andr345@gmail.com> --- drivers/ata/sata_nv.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c index 55a8eed..e8aba2f 100644 --- a/drivers/ata/sata_nv.c +++ b/drivers/ata/sata_nv.c @@ -579,6 +579,7 @@ MODULE_VERSION(DRV_VERSION); static int adma_enabled; static int swncq_enabled = 1; +static int parallel_scan = 0; static void nv_adma_register_mode(struct ata_port *ap) { @@ -2427,6 +2428,9 @@ static int nv_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) } else if (type == SWNCQ) nv_swncq_host_init(host); + if (parallel_scan) + host->flags |= ATA_HOST_PARALLEL_SCAN; + pci_set_master(pdev); return ata_host_activate(host, pdev->irq, ipriv->irq_handler, IRQF_SHARED, ipriv->sht); @@ -2526,4 +2530,6 @@ module_param_named(adma, adma_enabled, bool, 0444); MODULE_PARM_DESC(adma, "Enable use of ADMA (Default: true)"); module_param_named(swncq, swncq_enabled, bool, 0444); MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: true)"); +module_param_named(parallel_scan, parallel_scan, bool, 0444); +MODULE_PARM_DESC(parallel_scan, "Force parallel host scan (Default: false)"); -- 1.5.6.3
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