> Il giorno 8 set 2022, alle ore 04:46, Rory Chen <rory.c.chen@xxxxxxxxxxx> ha scritto: > > I change the comparison condition and it can eliminate the warning. Yep. The crash you reported also goes away? > < if (end >= iar->sector + 1 && end < iar->sector + iar->nr_sectors + 1) >> if (end >= iar->sector && end < iar->sector + iar->nr_sectors) > > I don't know if this change is appropriate Unfortunately your change conflicts with the standard code, taken from the original patches on access ranges [1]. I've CCed Damien, the author of this patch series. [1] https://lwn.net/ml/linux-block/20210909023545.1101672-2-damien.lemoal@xxxxxxx/ Thanks, Paolo > but bio_end_sector deducting 1 said by Tyler seems to make sense. > > From: Paolo Valente <paolo.valente@xxxxxxxxxx> > Sent: Thursday, August 25, 2022 10:45 PM > To: Tyler Erickson <tyler.erickson@xxxxxxxxxxx> > Cc: Rory Chen <rory.c.chen@xxxxxxxxxxx>; Arie van der Hoeven <arie.vanderhoeven@xxxxxxxxxxx>; Muhammad Ahmad <muhammad.ahmad@xxxxxxxxxxx>; linux-block@xxxxxxxxxxxxxxx <linux-block@xxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx>; Jan Kara <jack@xxxxxxx>; andrea.righi@xxxxxxxxxxxxx <andrea.righi@xxxxxxxxxxxxx>; glen.valante@xxxxxxxxxx <glen.valante@xxxxxxxxxx>; axboe@xxxxxxxxx <axboe@xxxxxxxxx>; Michael English <michael.english@xxxxxxxxxxx>; Andrew Ring <andrew.ring@xxxxxxxxxxx>; Varun Boddu <varunreddy.boddu@xxxxxxxxxxx> > Subject: Re: [PATCH 0/8] block, bfq: extend bfq to support multi-actuator drives > > > This message has originated from an External Source. Please use proper judgment and caution when opening attachments, clicking links, or responding to this email. > > > Hi > >> Il giorno 18 ago 2022, alle ore 17:40, Tyler Erickson <tyler.erickson@xxxxxxxxxxx> ha scritto: >> >> The libata layer is reporting correctly after the changes I submitted. >> >> The drive reports the actuator ranges as a starting LBA and a count of LBAs for the range. >> If the code reading the reported values simply does startingLBA + range, this is an incorrect ending LBA for that actuator. This is because LBAs are zero indexed and this simple addition is not taking that into account. >> The proper way to get the endingLBA is startingLBA + range - 1 to get the last LBA value for where to issue a final IO read/write to account for LBA values starting at zero rather than one. >> >> Here is an example from the output in SeaChest/openSeaChest: >> ====Concurrent Positioning Ranges==== >> >> Range# #Elements Lowest LBA # of LBAs >> 0 1 0 17578328064 >> 1 1 17578328064 17578328064 >> >> If using the incorrect formula to get the final LBA for actuator 0, you would get 17578328064, but this is the starting LBA reported by the drive for actuator 1. >> So to be consistent for all ranges, the final LBA for a given actuator should be calculated as starting LBA + range - 1. >> > > Ok > >> I had reached out to Seagate's T10 and T13 representatives for clarification and verification and this is most likely what is causing the error is a missing - 1 somewhere after getting the information reported by the device. They agreed that the reporting from the drive and the SCSI to ATA translation is correct. >> >> I'm not sure where this is being read and calculated, but it is not an error in the low-level libata or sd level of the kernel. It may be in bfq, or it may be in some other place after the sd layer. > > This apparent mistake is in the macro bio_end_sector (defined in > include/linux/bio.h), which seems to be translated as sector+size. > Jens, can you shed a light on this point? > > Thanks, > Paolo > >> I know there were some additions to read this and report it up the stack, but I did not think those were wrong as they seemed to pass the drive reported information up the stack. >> >> Tyler Erickson >> Seagate Technology >> >> >> Seagate Internal >> >> -----Original Message----- >> From: Rory Chen <rory.c.chen@xxxxxxxxxxx> >> Sent: Wednesday, August 10, 2022 6:59 AM >> To: Paolo Valente <paolo.valente@xxxxxxxxxx> >> Cc: Arie van der Hoeven <arie.vanderhoeven@xxxxxxxxxxx>; Muhammad Ahmad <muhammad.ahmad@xxxxxxxxxxx>; linux-block@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Jan Kara <jack@xxxxxxx>; andrea.righi@xxxxxxxxxxxxx; glen.valante@xxxxxxxxxx; axboe@xxxxxxxxx; Tyler Erickson <tyler.erickson@xxxxxxxxxxx>; Michael English <michael.english@xxxxxxxxxxx>; Andrew Ring <andrew.ring@xxxxxxxxxxx>; Varun Boddu <varunreddy.boddu@xxxxxxxxxxx> >> Subject: Re: [PATCH 0/8] block, bfq: extend bfq to support multi-actuator drives >> >> The block trace shows the start sector is 35156656120 and transfer length is 8 sectors, which is within the max LBA 35156656127 of drive. And this IO is completed successfully from the slice of parsed block trace though reporting the warning message. >> 8,64 7 13 0.039401337 19176 Q RA 35156656120 + 8 [systemd-udevd] >> 8,64 7 15 0.039403946 19176 P N [systemd-udevd] >> 8,64 7 16 0.039405132 19176 I RA 35156656120 + 8 [systemd-udevd] >> 8,64 7 18 0.039411554 19176 D RA 35156656120 + 8 [systemd-udevd] >> 8,64 0 40 0.039479055 0 C RA 35156656120 + 8 [0] >> >> It may need to know where calculate "bio_end_sector" value as 35156656128. I have patched libata and sd driver for Dual Actuator. >> >> >> >> From: Paolo Valente <paolo.valente@xxxxxxxxxx> >> Sent: Wednesday, August 10, 2022 6:22 PM >> To: Rory Chen <rory.c.chen@xxxxxxxxxxx> >> Cc: Arie van der Hoeven <arie.vanderhoeven@xxxxxxxxxxx>; Muhammad Ahmad <muhammad.ahmad@xxxxxxxxxxx>; linux-block@xxxxxxxxxxxxxxx <linux-block@xxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx>; Jan Kara <jack@xxxxxxx>; andrea.righi@xxxxxxxxxxxxx <andrea.righi@xxxxxxxxxxxxx>; glen.valante@xxxxxxxxxx <glen.valante@xxxxxxxxxx>; axboe@xxxxxxxxx <axboe@xxxxxxxxx>; Tyler Erickson <tyler.erickson@xxxxxxxxxxx>; Michael English <michael.english@xxxxxxxxxxx>; Andrew Ring <andrew.ring@xxxxxxxxxxx>; Varun Boddu <varunreddy.boddu@xxxxxxxxxxx> >> Subject: Re: [PATCH 0/8] block, bfq: extend bfq to support multi-actuator drives >> >> >> This message has originated from an External Source. Please use proper judgment and caution when opening attachments, clicking links, or responding to this email. >> >> >>> Il giorno 9 ago 2022, alle ore 05:47, Rory Chen <rory.c.chen@xxxxxxxxxxx> ha scritto: >>> >>> Resend the mail as plain text because previous mail with rich text >>> makes some mess and forget to add others at Seagate who worked on >>> validating the patch as well(Muhammad, Michael, Andrew, Varun,Tyler) >>> >>> Hi Paolo, >>> >> >> Hi >> >>> I am from Seagate China and face a problem when I'm evaluating the bfq patches. Could you please check? >>> Thanks >>> >>> Issue statement >>> When running performance test on bfq patch, I observed warning message "bfq_actuator_index: bio sector out of ranges: end=35156656128" and OS hung suddenly after some hours. >>> The warning message is reported from function bfq_actuator_index which determines IO request is in which index of actuators. The bio_end_sector is 35156656128 but the max LBA for the drive is 35156656127 so it's beyond the LBA range. >> >> Yep, this sanity check fails if the end sector of a new IO does not belong to any sector range. >> >>> I captured the block trace and didn't found request LBA 35156656128 instead only found max request LBA 35156656127. >> >> Maybe in the trace you see only start sectors? The failed check si performed on end sectors instead. >> >> At any rate, there seems to be an off-by-one error in the value(s) stored in the sector field(s) of the blk_independent_access_range data structure. >> >> I guess we may need some help/feedback from people competent on this stuff. >> >>> I'm not sure if this warning message is related to later OS hung. >>> >> >> Not easy to say. At any rate, we can try with a development version of bfq. It can help us detect the possible cause of this hang. But let's see where we get with this sector error first. >> >> Thank you for testing this extended version of bfq, Paolo >> >>> >>> Problem environment >>> Kernel base is 5.18.9 >>> Test HDD drive is Seagate ST18000NM0092 dual actuator SATA. >>> Actuator LBA mapping by reading VPD B9 Concurrent positioning ranges >>> VPD page: >>> LBA range number:0 >>> number of storage elements:1 >>> starting LBA:0x0 >>> number of LBAs:0x417c00000 [17578328064] LBA range number:1 number of >>> storage elements:1 starting LBA:0x417c00000 number of LBAs:0x417c00000 >>> [17578328064] >>> >>> >>> >>> >>> >>> From: Paolo Valente <paolo.valente@xxxxxxxxxx> >>> Sent: Thursday, June 23, 2022 8:53 AM >>> To: Jens Axboe <axboe@xxxxxxxxx> >>> Cc: linux-block@xxxxxxxxxxxxxxx <linux-block@xxxxxxxxxxxxxxx>; >>> linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx>; >>> jack@xxxxxxx <jack@xxxxxxx>; andrea.righi@xxxxxxxxxxxxx >>> <andrea.righi@xxxxxxxxxxxxx>; glen.valante@xxxxxxxxxx >>> <glen.valante@xxxxxxxxxx>; Arie van der Hoeven >>> <arie.vanderhoeven@xxxxxxxxxxx>; Paolo Valente >>> <paolo.valente@xxxxxxxxxx> >>> Subject: [PATCH 0/8] block, bfq: extend bfq to support multi-actuator >>> drives >>> >>> >>> This message has originated from an External Source. Please use proper judgment and caution when opening attachments, clicking links, or responding to this email. >>> >>> >>> Hi, >>> this patch series extends BFQ so as to optimize I/O dispatch to >>> multi-actuator drives. In particular, this extension addresses the >>> following issue. Multi-actuator drives appear as a single device to >>> the I/O subsystem [1]. Yet they address commands to different >>> actuators internally, as a function of Logical Block Addressing >>> (LBAs). A given sector is reachable by only one of the actuators. For >>> example, Seagate's Serial Advanced Technology Attachment (SATA) >>> version contains two actuators and maps the lower half of the SATA LBA >>> space to the lower actuator and the upper half to the upper actuator. >>> >>> Evidently, to fully utilize actuators, no actuator must be left idle >>> or underutilized while there is pending I/O for it. To reach this >>> goal, the block layer must somehow control the load of each actuator >>> individually. This series enriches BFQ with such a per-actuator >>> control, as a first step. Then it also adds a simple mechanism for >>> guaranteeing that actuators with pending I/O are never left idle. >>> >>> See [1] for a more detailed overview of the problem and of the >>> solutions implemented in this patch series. There you will also find >>> some preliminary performance results. >>> >>> Thanks, >>> Paolo >>> >>> [1] >>> https://secure-web.cisco.com/1hcxnN1C3h1nW7mby7S66_LE8szirQwbQI0fBpYeP >>> rA0GTWfyuQyl0GpZaOn32xMSkNT0BUQWloDHFzZ23aYDZdi8NfdrEFLY9pQDBblIvn08LR >>> iTVoIOUC8zWSG_r2PCyLtx3ppZq5cWOib_8azxteRRcbKWGdbLPSqg9hfSJSqltth0ByLO >>> NHEoI3p3e9QNIn6nVAeQbsT3aOQe-F95XrQvaPrFJXx6RGL9kDXyfkbXIHcdcLBf895gYB >>> Fn5S2WjBDQq2kzDzZOlc1HekRUhg0qDQcFY6NydVfrqNfLbpAHAth6KyREscQhVTMVREEV >>> a1b6bQByX6grF5pn3pTIo0lODyfX6yRmcbReSYNfOZ65ZPvp-nH530FQ-5nXoRxFf74WIK >>> DrNTALs3xQvg03DH4jLez-T2M9xEu-sfEDAEdTGF7BcnmBW6vrPO4_p3k4/https%3A%2F >>> %2Fwww.linaro.org%2Fblog%2Fbudget-fair-queueing-bfq-linux-io-scheduler >>> -optimizations-for-multi-actuator-sata-hard-drives%2F >>> >>> Davide Zini (3): >>> block, bfq: split also async bfq_queues on a per-actuator basis >>> block, bfq: inject I/O to underutilized actuators block, bfq: balance >>> I/O injection among underutilized actuators >>> >>> Federico Gavioli (1): >>> block, bfq: retrieve independent access ranges from request queue >>> >>> Paolo Valente (4): >>> block, bfq: split sync bfq_queues on a per-actuator basis block, >>> bfq: forbid stable merging of queues associated with different >>> actuators >>> block, bfq: turn scalar fields into arrays in bfq_io_cq block, bfq: >>> turn BFQ_NUM_ACTUATORS into BFQ_MAX_ACTUATORS >>> >>> block/bfq-cgroup.c | 97 +++++---- >>> block/bfq-iosched.c | 488 +++++++++++++++++++++++++++++--------------- >>> block/bfq-iosched.h | 149 ++++++++++---- >>> block/bfq-wf2q.c | 2 +- >>> 4 files changed, 493 insertions(+), 243 deletions(-) >>> >>> -- >>> 2.20.1 >>> >>> >>> Seagate Internal >>> >>> Seagate Internal >> >> Seagate Internal > > Seagate Internal
