| Message ID | m2gda824cf31004131746o15be77b1n7af6fac42ce25280@mail.gmail.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
Hello, On 04/14/2010 09:46 AM, Grant Grundler wrote: > In 2009, While running "cache read" performance test of drives behind > SII PMP we encountered a "all 5 drives" timeout on more than 30% of the > machines under test. This patch reduces the rate by a factor of about 70. > Low enough that we didn't care to further investigate the issue. Interesting. > Performance impact with any sort of "normal" use was ~2%+ CPU and less > than 1% throughput degradation. Worst case impact (cached read) was > 6% IOPS reduction. This is with NCQ off (q=1) but I believe FIS based > switching enabled in the SATA driver. Given the general flakiness of the device, I'm more than willing to pay some overhead for stability and the performance hit seems pretty small. > @@ -260,12 +262,28 @@ static int sata_pmp_configure(struct ata_device > *dev, int print_info) > goto fail; > } > > + /* For Sil3726, disable sending Early R_OK */ > + if (vendor == 0x1095 && devid == 0x3726) { Isn't this also applicable to 4723 and 4726? > diff --git a/include/linux/ata.h b/include/linux/ata.h > index 700c5b9..18fc208 100644 > --- a/include/linux/ata.h > +++ b/include/linux/ata.h > @@ -386,6 +386,7 @@ enum { > SATA_PMP_GSCR_ERROR_EN = 33, > SATA_PMP_GSCR_FEAT = 64, > SATA_PMP_GSCR_FEAT_EN = 96, > + SATA_PMP_GSCR_SII_POL = 129, /* VENDOR : Silicon Image 3726/4726 */ Can you plesae define it inside libata-pmp.c? ata.h only contains stuff defined by the ATA standard. Other than the above nitpicks, Acked-by: Tejun Heo <tj@kernel.org> Thanks.
On Wed, Apr 14, 2010 at 5:31 PM, Tejun Heo <tj@kernel.org> wrote: > Hello, > > On 04/14/2010 09:46 AM, Grant Grundler wrote: >> In 2009, While running "cache read" performance test of drives behind >> SII PMP we encountered a "all 5 drives" timeout on more than 30% of the >> machines under test. This patch reduces the rate by a factor of about 70. >> Low enough that we didn't care to further investigate the issue. > > Interesting. > >> Performance impact with any sort of "normal" use was ~2%+ CPU and less >> than 1% throughput degradation. Worst case impact (cached read) was >> 6% IOPS reduction. This is with NCQ off (q=1) but I believe FIS based >> switching enabled in the SATA driver. > > Given the general flakiness of the device, I'm more than willing to > pay some overhead for stability and the performance hit seems pretty > small. > >> @@ -260,12 +262,28 @@ static int sata_pmp_configure(struct ata_device >> *dev, int print_info) >> goto fail; >> } >> >> + /* For Sil3726, disable sending Early R_OK */ >> + if (vendor == 0x1095 && devid == 0x3726) { > > Isn't this also applicable to 4723 and 4726? Sorry, I don't know why I included 4726 in the Subject line since I only tested with 3726. I expect it would apply to 4726 but someone who knows the internals of both would have to confirm that. I don't know anything about 4723. > >> diff --git a/include/linux/ata.h b/include/linux/ata.h >> index 700c5b9..18fc208 100644 >> --- a/include/linux/ata.h >> +++ b/include/linux/ata.h >> @@ -386,6 +386,7 @@ enum { >> SATA_PMP_GSCR_ERROR_EN = 33, >> SATA_PMP_GSCR_FEAT = 64, >> SATA_PMP_GSCR_FEAT_EN = 96, >> + SATA_PMP_GSCR_SII_POL = 129, /* VENDOR : Silicon Image 3726/4726 */ > > Can you plesae define it inside libata-pmp.c? Yes. I'll resubmit with "SII_POL" defined "locally". > ata.h only contains stuff defined by the ATA standard. Ah ok. I didn't realize that. > > Other than the above nitpicks, > > Acked-by: Tejun Heo <tj@kernel.org> Thanks for the Ack/Review! grant > > Thanks. > > -- > tejun > -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c index 00305f4..69bb203 100644 --- a/drivers/ata/libata-pmp.c +++ b/drivers/ata/libata-pmp.c @@ -235,6 +235,8 @@ static int sata_pmp_configure(struct ata_device *dev, int print_info) { struct ata_port *ap = dev->link->ap; u32 *gscr = dev->gscr; + u16 vendor = sata_pmp_gscr_vendor(gscr); + u16 devid = sata_pmp_gscr_devid(gscr); unsigned int err_mask = 0; const char *reason; int nr_ports, rc; @@ -260,12 +262,28 @@ static int sata_pmp_configure(struct ata_device *dev, int print_info) goto fail; } + /* For Sil3726, disable sending Early R_OK */ + if (vendor == 0x1095 && devid == 0x3726) { + u32 reg; + err_mask = sata_pmp_read(&ap->link, SATA_PMP_GSCR_SII_POL, ®); + if (err_mask) { + rc = -EIO; + reason = "failed to read Sil3726 Private Register"; + goto fail; + } + reg &= ~0x1; + err_mask = sata_pmp_write(&ap->link, SATA_PMP_GSCR_SII_POL, reg); + if (err_mask) { + rc = -EIO; + reason = "failed to write Sil3726 Private Register"; + goto fail; + } + } + if (print_info) { ata_dev_printk(dev, KERN_INFO, "Port Multiplier %s, " "0x%04x:0x%04x r%d, %d ports, feat 0x%x/0x%x\n", - sata_pmp_spec_rev_str(gscr), - sata_pmp_gscr_vendor(gscr), - sata_pmp_gscr_devid(gscr), + sata_pmp_spec_rev_str(gscr), vendor, devid, sata_pmp_gscr_rev(gscr), nr_ports, gscr[SATA_PMP_GSCR_FEAT_EN], gscr[SATA_PMP_GSCR_FEAT]); diff --git a/include/linux/ata.h b/include/linux/ata.h index 700c5b9..18fc208 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -386,6 +386,7 @@ enum { SATA_PMP_GSCR_ERROR_EN = 33, SATA_PMP_GSCR_FEAT = 64, SATA_PMP_GSCR_FEAT_EN = 96, + SATA_PMP_GSCR_SII_POL = 129, /* VENDOR : Silicon Image 3726/4726 */ SATA_PMP_PSCR_STATUS = 0, SATA_PMP_PSCR_ERROR = 1,