Changes in Kconfig.iosched

4a6a7bc2 - block: Default to use cgroup support for BFQ

Mon, 30 Jan 2023 12:12:40 +0000

block: Default to use cgroup support for BFQAssuming that both Kconfig options, BLK_CGROUP and IOSCHED_BFQ are set, wemost likely want cgroup support for BFQ too (BFQ_GROUP_IOSCHED), so let'smake it default y.Signed-off-by: Ulf Hansson Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20230130121240.159456-1-ulf.hansson@linaro.orgSigned-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

5ef16305 - block: only build the icq tracking code when needed

Thu, 09 Dec 2021 06:31:31 +0000

block: only build the icq tracking code when neededOnly bfq needs to code to track icq, so make it conditional.Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20211209063131.18537-12-hch@lst.deSigned-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

c50fca55 - block: simplify Kconfig files

Mon, 27 Sep 2021 13:59:58 +0000

block: simplify Kconfig filesEverything under block/ depends on BLOCK. BLOCK_HOLDER_DEPRECATED isselected from drivers/md/Kconfig, which is entirely dependent on BLOCK.Extend the 'if BLOCK' ... 'endif' so it covers the whole block/Kconfig.Also, clean up the definition of BLOCK_COMPAT and BLK_MQ_PCI becauseCOMPAT and PCI are boolean.Signed-off-by: Masahiro Yamada Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210927140000.866249-3-masahiroy@kernel.orgSigned-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

0f783995 - Revert "block/mq-deadline: Add cgroup support"

Wed, 11 Aug 2021 17:41:45 +0000

Revert "block/mq-deadline: Add cgroup support"This reverts commit 08a9ad8bf607 ("block/mq-deadline: Add cgroup support")and a follow-up commit c06bc5a3fb42 ("block/mq-deadline: Remove aWARN_ON_ONCE() call"). The added cgroup support has the following issues:* It breaks cgroup interface file format rule by adding custom elements to a nested key-value file.* It registers mq-deadline as a cgroup-aware policy even though all it's doing is collecting per-cgroup stats. Even if we need these stats, this isn't the right way to add them.* It hasn't been reviewed from cgroup side.Cc: Bart Van Assche Cc: Jens Axboe Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

08a9ad8b - block/mq-deadline: Add cgroup support

Fri, 18 Jun 2021 00:44:55 +0000

block/mq-deadline: Add cgroup supportMaintain statistics per cgroup and export these to user space. Thesestatistics are essential for verifying whether the proper I/O prioritieshave been assigned to requests. An example of the statistics data withthis patch applied:$ cat /sys/fs/cgroup/io.stat11:2 rbytes=0 wbytes=0 rios=3 wios=0 dbytes=0 dios=0 [NONE] dispatched=0 inserted=0 merged=171 [RT] dispatched=0 inserted=0 merged=0 [BE] dispatched=0 inserted=0 merged=0 [IDLE] dispatched=0 inserted=0 merged=08:32 rbytes=2142720 wbytes=0 rios=105 wios=0 dbytes=0 dios=0 [NONE] dispatched=0 inserted=0 merged=171 [RT] dispatched=0 inserted=0 merged=0 [BE] dispatched=0 inserted=0 merged=0 [IDLE] dispatched=0 inserted=0 merged=0Cc: Damien Le Moal Cc: Hannes Reinecke Cc: Christoph Hellwig Cc: Ming Lei Cc: Johannes Thumshirn Cc: Himanshu Madhani Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20210618004456.7280-16-bvanassche@acm.orgSigned-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

a7f7f624 - treewide: replace '---help---' in Kconfig files with 'help'

Sat, 13 Jun 2020 16:50:22 +0000

treewide: replace '---help---' in Kconfig files with 'help'Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over'---help---'"), the number of '---help---' has been graduallydecreasing, but there are still more than 2400 instances.This commit finishes the conversion. While I touched the lines,I also fixed the indentation.There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---'In order to convert all of them to 1 tab + 'help', I ran thefollowing commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'Signed-off-by: Masahiro Yamada List of files: /linux-6.15/block/Kconfig.iosched

1d156646 - blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT

Thu, 07 Nov 2019 19:18:04 +0000

blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTATblkg_rwstat is now only used by bfq-iosched and blk-throtl when oncgroup1. Let's move it into its own files and gate it behind a configoption.Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

898bd37a - docs: block: convert to ReST

Thu, 18 Apr 2019 22:45:00 +0000

docs: block: convert to ReSTRename the block documentation files to ReST, add anindex for them and adjust in order to produce a nice htmloutput via the Sphinx build system.At its new index.rst, let's add a :orphan: while this is not linked tothe main index.rst file, in order to avoid build warnings.Signed-off-by: Mauro Carvalho Chehab List of files: /linux-6.15/block/Kconfig.iosched

8060c47b - block: rename CONFIG_DEBUG_BLK_CGROUP to CONFIG_BFQ_CGROUP_DEBUG

Thu, 06 Jun 2019 10:26:24 +0000

block: rename CONFIG_DEBUG_BLK_CGROUP to CONFIG_BFQ_CGROUP_DEBUGThis option is entirely bfq specific, give it an appropinquate name.Also make it depend on CONFIG_BFQ_GROUP_IOSCHED in Kconfig, as allthe functionality already does so anyway.Acked-by: Tejun Heo Acked-by: Paolo Valente Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

f382fb0b - block: remove legacy IO schedulers

Fri, 12 Oct 2018 16:14:46 +0000

block: remove legacy IO schedulersRetain the deadline documentation, as that carries over to mq-deadlineas well.Tested-by: Ming Lei Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

1306ad4e - block: remove redundant 'default n' from Kconfig-s

Tue, 09 Oct 2018 14:32:54 +0000

block: remove redundant 'default n' from Kconfig-s'default n' is the default value for any bool or tristate Kconfigsetting so there is no need to write it explicitly.Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOOis not set' for visible symbols") the Kconfig behavior is the sameregardless of 'default n' being present or not: ... One side effect of (and the main motivation for) this change is making the following two definitions behave exactly the same: config FOO bool config FOO bool default n With this change, neither of these will generate a '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied). That might make it clearer to people that a bare 'default n' is redundant. ...Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

b2441318 - License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Wed, 01 Nov 2017 14:07:57 +0000

License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseMany source files in the tree are missing licensing information, whichmakes it harder for compliance tools to determine the correct license.By default all files without license information are under the defaultlicense of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'SPDX license identifier. The SPDX identifier is a legally bindingshorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart andPhilippe Ombredanne.How this work was done:Patches were generated and checked against linux-4.14-rc6 for a subset ofthe use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up caseswhere non-standard license headers were used, and references to licensehad to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied toa file was done in a spreadsheet of side by side results from of theoutput of two independent scanners (ScanCode & Windriver) producing SPDXtag:value files created by Philippe Ombredanne. Philippe prepared thebase worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 filesassessed. Kate Stewart did a file by file comparison of the scannerresults in the spreadsheet to determine which SPDX license identifier(s)to be applied to the file. She confirmed any determination that was notimmediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines).All documentation files were explicitly excluded.The following heuristics were used to determine which SPDX licenseidentifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time.In total, over 70 hours of logged manual review was done on thespreadsheet to determine the SPDX license identifiers to apply to thesource files by Kate, Philippe, Thomas and, in some cases, confirmationby lawyers working with the Linux Foundation.Kate also obtained a third independent scan of the 4.13 code base fromFOSSology, and compared selected files where the other two scannersdisagreed against that SPDX file, to see if there was new insights. TheWindriver scanner is based on an older version of FOSSology in part, sothey are related.Thomas did random spot checks in about 500 files from the spreadsheetsfor the uapi headers and agreed with SPDX license identifier in thefiles he inspected. For the non-uapi files Thomas did random spot checksin about 15000 files.In initial set of patches against 4.14-rc6, 3 files were found to havecopy/paste license identifier errors, and have been fixed to reflect thecorrect identifier.Additionally Philippe spent 10 hours this week doing a detailed manualinspection and review of the 12,461 patched files from the initial patchversion early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correctThis produced a worksheet with 20 files needing minor correction. Thisworksheet was then exported into 3 different .csv files for thedifferent types of files to be modified.These .csv files were then reviewed by Greg. Thomas wrote a script toparse the csv files and add the proper SPDX tag to the file, in theformat that the file expected. This script was further refined by Gregbased on the output to detect more types of files automatically and todistinguish between header and source .c files (which need differentcomment types.) Finally Greg ran the script using the .csv files togenerate the patches.Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/block/Kconfig.iosched

e21b7a0b - block, bfq: add full hierarchical scheduling and cgroups support

Wed, 12 Apr 2017 16:23:08 +0000

block, bfq: add full hierarchical scheduling and cgroups supportAdd complete support for full hierarchical scheduling, with a cgroupsinterface. Full hierarchical scheduling is implemented through the'entity' abstraction: both bfq_queues, i.e., the internal BFQ queuesassociated with processes, and groups are represented in general byentities. Given the bfq_queues associated with the processes belongingto a given group, the entities representing these queues are sons ofthe entity representing the group. At higher levels, if a group, sayG, contains other groups, then the entity representing G is the parententity of the entities representing the groups in G.Hierarchical scheduling is performed as follows: if the timestamps ofa leaf entity (i.e., of a bfq_queue) change, and such a change letsthe entity become the next-to-serve entity for its parent entity, thenthe timestamps of the parent entity are recomputed as a function ofthe budget of its new next-to-serve leaf entity. If the parent entitybelongs, in its turn, to a group, and its new timestamps let it becomethe next-to-serve for its parent entity, then the timestamps of thelatter parent entity are recomputed as well, and so on. When a newbfq_queue must be set in service, the reverse path is followed: thenext-to-serve highest-level entity is chosen, then its next-to-servechild entity, and so on, until the next-to-serve leaf entity isreached, and the bfq_queue that this entity represents is set inservice.Writeback is accounted for on a per-group basis, i.e., for each group,the async I/O requests of the processes of the group are enqueued in adistinct bfq_queue, and the entity associated with this queue is achild of the entity associated with the group.Weights can be assigned explicitly to groups and processes through thecgroups interface, differently from what happens, for singleprocesses, if the cgroups interface is not used (as explained in thedescription of the previous patch). In particular, since each node hasa full scheduler, each group can be assigned its own weight.Signed-off-by: Fabio Checconi Signed-off-by: Paolo Valente Signed-off-by: Arianna Avanzini Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

aee69d78 - block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler

Wed, 19 Apr 2017 14:29:02 +0000

block, bfq: introduce the BFQ-v0 I/O scheduler as an extra schedulerWe tag as v0 the version of BFQ containing only BFQ's engine plushierarchical support. BFQ's engine is introduced by this commit, whilehierarchical support is added by next commit. We use the v0 tag todistinguish this minimal version of BFQ from the versions containingalso the features and the improvements added by next commits. BFQ-v0coincides with the version of BFQ submitted a few years ago [1], apartfrom the introduction of preemption, described below.BFQ is a proportional-share I/O scheduler, whose general structure,plus a lot of code, are borrowed from CFQ.- Each process doing I/O on a device is associated with a weight and a (bfq_)queue.- BFQ grants exclusive access to the device, for a while, to one queue (process) at a time, and implements this service model by associating every queue with a budget, measured in number of sectors. - After a queue is granted access to the device, the budget of the queue is decremented, on each request dispatch, by the size of the request. - The in-service queue is expired, i.e., its service is suspended, only if one of the following events occurs: 1) the queue finishes its budget, 2) the queue empties, 3) a "budget timeout" fires. - The budget timeout prevents processes doing random I/O from holding the device for too long and dramatically reducing throughput. - Actually, as in CFQ, a queue associated with a process issuing sync requests may not be expired immediately when it empties. In contrast, BFQ may idle the device for a short time interval, giving the process the chance to go on being served if it issues a new request in time. Device idling typically boosts the throughput on rotational devices, if processes do synchronous and sequential I/O. In addition, under BFQ, device idling is also instrumental in guaranteeing the desired throughput fraction to processes issuing sync requests (see [2] for details). - With respect to idling for service guarantees, if several processes are competing for the device at the same time, but all processes (and groups, after the following commit) have the same weight, then BFQ guarantees the expected throughput distribution without ever idling the device. Throughput is thus as high as possible in this common scenario. - Queues are scheduled according to a variant of WF2Q+, named B-WF2Q+, and implemented using an augmented rb-tree to preserve an O(log N) overall complexity. See [2] for more details. B-WF2Q+ is also ready for hierarchical scheduling. However, for a cleaner logical breakdown, the code that enables and completes hierarchical support is provided in the next commit, which focuses exactly on this feature. - B-WF2Q+ guarantees a tight deviation with respect to an ideal, perfectly fair, and smooth service. In particular, B-WF2Q+ guarantees that each queue receives a fraction of the device throughput proportional to its weight, even if the throughput fluctuates, and regardless of: the device parameters, the current workload and the budgets assigned to the queue. - The last, budget-independence, property (although probably counterintuitive in the first place) is definitely beneficial, for the following reasons: - First, with any proportional-share scheduler, the maximum deviation with respect to an ideal service is proportional to the maximum budget (slice) assigned to queues. As a consequence, BFQ can keep this deviation tight not only because of the accurate service of B-WF2Q+, but also because BFQ *does not* need to assign a larger budget to a queue to let the queue receive a higher fraction of the device throughput. - Second, BFQ is free to choose, for every process (queue), the budget that best fits the needs of the process, or best leverages the I/O pattern of the process. In particular, BFQ updates queue budgets with a simple feedback-loop algorithm that allows a high throughput to be achieved, while still providing tight latency guarantees to time-sensitive applications. When the in-service queue expires, this algorithm computes the next budget of the queue so as to: - Let large budgets be eventually assigned to the queues associated with I/O-bound applications performing sequential I/O: in fact, the longer these applications are served once got access to the device, the higher the throughput is. - Let small budgets be eventually assigned to the queues associated with time-sensitive applications (which typically perform sporadic and short I/O), because, the smaller the budget assigned to a queue waiting for service is, the sooner B-WF2Q+ will serve that queue (Subsec 3.3 in [2]).- Weights can be assigned to processes only indirectly, through I/O priorities, and according to the relation: weight = 10 * (IOPRIO_BE_NR - ioprio). The next patch provides, instead, a cgroups interface through which weights can be assigned explicitly.- If several processes are competing for the device at the same time, but all processes and groups have the same weight, then BFQ guarantees the expected throughput distribution without ever idling the device. It uses preemption instead. Throughput is then much higher in this common scenario.- ioprio classes are served in strict priority order, i.e., lower-priority queues are not served as long as there are higher-priority queues. Among queues in the same class, the bandwidth is distributed in proportion to the weight of each queue. A very thin extra bandwidth is however guaranteed to the Idle class, to prevent it from starving.- If the strict_guarantees parameter is set (default: unset), then BFQ - always performs idling when the in-service queue becomes empty; - forces the device to serve one I/O request at a time, by dispatching a new request only if there is no outstanding request. In the presence of differentiated weights or I/O-request sizes, both the above conditions are needed to guarantee that every queue receives its allotted share of the bandwidth (see Documentation/block/bfq-iosched.txt for more details). Setting strict_guarantees may evidently affect throughput.[1] https://lkml.org/lkml/2008/4/1/234 https://lkml.org/lkml/2008/11/11/148[2] P. Valente and M. Andreolini, "Improving Application Responsiveness with the BFQ Disk I/O Scheduler", Proceedings of the 5th Annual International Systems and Storage Conference (SYSTOR '12), June 2012. Slightly extended version: http://algogroup.unimore.it/people/paolo/disk_sched/bfq-v1-suite- results.pdfSigned-off-by: Fabio Checconi Signed-off-by: Paolo Valente Signed-off-by: Arianna Avanzini Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

00e04393 - blk-mq: introduce Kyber multiqueue I/O scheduler

Fri, 14 Apr 2017 08:00:02 +0000

blk-mq: introduce Kyber multiqueue I/O schedulerThe Kyber I/O scheduler is an I/O scheduler for fast devices designed toscale to multiple queues. Users configure only two knobs, the targetread and synchronous write latencies, and the scheduler tunes itself toachieve that latency goal.The implementation is based on "tokens", built on top of the scalablebitmap library. Tokens serve as a mechanism for limiting requests. Thereare two tiers of tokens: queueing tokens and dispatch tokens.A queueing token is required to allocate a request. In fact, thesetokens are actually the blk-mq internal scheduler tags, but thescheduler manages the allocation directly in order to implement itspolicy.Dispatch tokens are device-wide and split up into two schedulingdomains: reads vs. writes. Each hardware queue dispatches batchesround-robin between the scheduling domains as long as tokens areavailable for that domain.These tokens can be used as the mechanism to enable various policies.The policy Kyber uses is inspired by active queue management techniquesfor network routing, similar to blk-wbt. The scheduler monitorslatencies and scales the number of dispatch tokens accordingly. Queueingtokens are used to prevent starvation of synchronous requests byasynchronous requests.Various extensions are possible, including better heuristics and ionicesupport. The new scheduler isn't set as the default yet.Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

b86dd815 - block: get rid of blk-mq default scheduler choice Kconfig entries

Wed, 22 Feb 2017 20:19:45 +0000

block: get rid of blk-mq default scheduler choice Kconfig entriesThe wording in the entries were poor and not understandableby even deities. Kill the selection for default block scheduler,and impose a policy with sane defaults.Architected-by: Linus Torvalds Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

d3484991 - blk-mq-sched: allow setting of default IO scheduler

Fri, 13 Jan 2017 21:43:58 +0000

blk-mq-sched: allow setting of default IO schedulerAdd Kconfig entries to manage what devices get assigned an MQscheduler, and add a blk-mq flag for drivers to opt out of scheduling.The latter is useful for admin type queues that still allocate a blk-mqqueue and tag set, but aren't use for normal IO.Signed-off-by: Jens Axboe Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval List of files: /linux-6.15/block/Kconfig.iosched

945ffb60 - mq-deadline: add blk-mq adaptation of the deadline IO scheduler

Sun, 15 Jan 2017 00:11:11 +0000

mq-deadline: add blk-mq adaptation of the deadline IO schedulerThis is basically identical to deadline-iosched, except it registersas a MQ capable scheduler. This is still a single queue design.Signed-off-by: Jens Axboe Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval List of files: /linux-6.15/block/Kconfig.iosched

32e380ae - blkcg: make CONFIG_BLK_CGROUP bool

Mon, 05 Mar 2012 21:14:54 +0000

blkcg: make CONFIG_BLK_CGROUP boolBlock cgroup core can be built as module; however, it isn't too usefulas blk-throttle can only be built-in and cfq-iosched is usually thedefault built-in scheduler. Scheduled blkcg cleanup requires callinginto blkcg from block core. To simplify that, disallow building blkcgas module by making CONFIG_BLK_CGROUP bool.If building blkcg core as module really matters, which I doubt, we canrevisit it after blkcg API cleanup.-v2: Vivek pointed out that IOSCHED_CFQ was incorrectly updated to depend on BLK_CGROUP. Fixed.Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched

afc24d49 - blk-cgroup: config options re-arrangement

Mon, 26 Apr 2010 17:27:56 +0000

blk-cgroup: config options re-arrangementThis patch fixes few usability and configurability issues.o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers.o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu.Signed-off-by: Vivek Goyal Acked-by: Divyesh Shah Reviewed-by: Gui Jianfeng Signed-off-by: Jens Axboe List of files: /linux-6.15/block/Kconfig.iosched