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author | Tejun Heo <htejun@gmail.com> | 2008-05-20 02:17:52 +0900 |
---|---|---|
committer | Jeff Garzik <jgarzik@redhat.com> | 2008-07-14 15:59:32 -0400 |
commit | 0a2c0f56159999e20015241d3b8fa89b1ab14309 (patch) | |
tree | 2c516452d3b3f85e9a4092b6092160e123d5f5d4 /drivers/ata/libata-eh.c | |
parent | 341c2c958ec7bdd9f54733a8b0b432fe76842a82 (diff) | |
download | kernel_samsung_smdk4412-0a2c0f56159999e20015241d3b8fa89b1ab14309.zip kernel_samsung_smdk4412-0a2c0f56159999e20015241d3b8fa89b1ab14309.tar.gz kernel_samsung_smdk4412-0a2c0f56159999e20015241d3b8fa89b1ab14309.tar.bz2 |
libata: improve EH retry delay handling
EH retries were delayed by 5 seconds to ensure that resets don't occur
back-to-back. However, this 5 second delay is superflous or excessive
in many cases. For example, after IDENTIFY times out, there's no
reason to wait five more seconds before retrying.
This patch adds ehc->last_reset timestamp and record the timestamp for
the last reset trial or success and uses it to space resets by
ATA_EH_RESET_COOL_DOWN which is 5 secs and removes unconditional 5 sec
sleeps.
As this change makes inter-try waits often shorter and they're
redundant in nature, this patch also removes the "retrying..."
messages.
While at it, convert explicit rounding up division to DIV_ROUND_UP().
This change speeds up EH in many cases w/o sacrificing robustness.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/libata-eh.c')
-rw-r--r-- | drivers/ata/libata-eh.c | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 08dd07f..5b5ae63 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -67,6 +67,9 @@ enum { ATA_ECAT_DUBIOUS_UNK_DEV = 7, ATA_ECAT_NR = 8, + /* always put at least this amount of time between resets */ + ATA_EH_RESET_COOL_DOWN = 5000, + /* Waiting in ->prereset can never be reliable. It's * sometimes nice to wait there but it can't be depended upon; * otherwise, we wouldn't be resetting. Just give it enough @@ -485,6 +488,9 @@ void ata_scsi_error(struct Scsi_Host *host) if (ata_ncq_enabled(dev)) ehc->saved_ncq_enabled |= 1 << devno; } + + /* set last reset timestamp to some time in the past */ + ehc->last_reset = jiffies - 60 * HZ; } ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS; @@ -2088,11 +2094,17 @@ int ata_eh_reset(struct ata_link *link, int classify, /* * Prepare to reset */ + now = jiffies; + deadline = ata_deadline(ehc->last_reset, ATA_EH_RESET_COOL_DOWN); + if (time_before(now, deadline)) + schedule_timeout_uninterruptible(deadline - now); + spin_lock_irqsave(ap->lock, flags); ap->pflags |= ATA_PFLAG_RESETTING; spin_unlock_irqrestore(ap->lock, flags); ata_eh_about_to_do(link, NULL, ATA_EH_RESET); + ehc->last_reset = jiffies; ata_link_for_each_dev(dev, link) { /* If we issue an SRST then an ATA drive (not ATAPI) @@ -2158,6 +2170,7 @@ int ata_eh_reset(struct ata_link *link, int classify, /* * Perform reset */ + ehc->last_reset = jiffies; if (ata_is_host_link(link)) ata_eh_freeze_port(ap); @@ -2278,6 +2291,7 @@ int ata_eh_reset(struct ata_link *link, int classify, /* reset successful, schedule revalidation */ ata_eh_done(link, NULL, ATA_EH_RESET); + ehc->last_reset = jiffies; ehc->i.action |= ATA_EH_REVALIDATE; rc = 0; @@ -2304,9 +2318,9 @@ int ata_eh_reset(struct ata_link *link, int classify, if (time_before(now, deadline)) { unsigned long delta = deadline - now; - ata_link_printk(link, KERN_WARNING, "reset failed " - "(errno=%d), retrying in %u secs\n", - rc, (jiffies_to_msecs(delta) + 999) / 1000); + ata_link_printk(link, KERN_WARNING, + "reset failed (errno=%d), retrying in %u secs\n", + rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000)); while (delta) delta = schedule_timeout_uninterruptible(delta); @@ -2623,7 +2637,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset, { struct ata_link *link; struct ata_device *dev; - int nr_failed_devs, nr_disabled_devs; + int nr_failed_devs; int rc; unsigned long flags; @@ -2666,7 +2680,6 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset, retry: rc = 0; nr_failed_devs = 0; - nr_disabled_devs = 0; /* if UNLOADING, finish immediately */ if (ap->pflags & ATA_PFLAG_UNLOADING) @@ -2733,8 +2746,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset, dev_fail: nr_failed_devs++; - if (ata_eh_handle_dev_fail(dev, rc)) - nr_disabled_devs++; + ata_eh_handle_dev_fail(dev, rc); if (ap->pflags & ATA_PFLAG_FROZEN) { /* PMP reset requires working host port. @@ -2746,18 +2758,8 @@ dev_fail: } } - if (nr_failed_devs) { - if (nr_failed_devs != nr_disabled_devs) { - ata_port_printk(ap, KERN_WARNING, "failed to recover " - "some devices, retrying in 5 secs\n"); - ssleep(5); - } else { - /* no device left to recover, repeat fast */ - msleep(500); - } - + if (nr_failed_devs) goto retry; - } out: if (rc && r_failed_link) |