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docs: block: Fix grammar and spelling mistakes in bfq-iosched.rst
This patch corrects several grammar and spelling errors in the Documentation/block/bfq-iosched.rst file. These changes improve the clarity and readability of the documentation. Signed-off-by: Karol Przybylski <karprzy7@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240814155558.3672833-1-karprzy7@gmail.com
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@ -9,7 +9,7 @@ controllers), BFQ's main features are:
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- BFQ guarantees a high system and application responsiveness, and a
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low latency for time-sensitive applications, such as audio or video
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players;
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- BFQ distributes bandwidth, and not just time, among processes or
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- BFQ distributes bandwidth, not just time, among processes or
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groups (switching back to time distribution when needed to keep
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throughput high).
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@ -111,7 +111,7 @@ Higher speed for code-development tasks
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If some additional workload happens to be executed in parallel, then
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BFQ executes the I/O-related components of typical code-development
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tasks (compilation, checkout, merge, ...) much more quickly than CFQ,
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tasks (compilation, checkout, merge, etc.) much more quickly than CFQ,
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NOOP or DEADLINE.
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High throughput
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@ -127,9 +127,9 @@ Strong fairness, bandwidth and delay guarantees
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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BFQ distributes the device throughput, and not just the device time,
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among I/O-bound applications in proportion their weights, with any
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among I/O-bound applications in proportion to their weights, with any
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workload and regardless of the device parameters. From these bandwidth
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guarantees, it is possible to compute tight per-I/O-request delay
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guarantees, it is possible to compute a tight per-I/O-request delay
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guarantees by a simple formula. If not configured for strict service
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guarantees, BFQ switches to time-based resource sharing (only) for
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applications that would otherwise cause a throughput loss.
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@ -199,7 +199,7 @@ plus a lot of code, are borrowed from CFQ.
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- On flash-based storage with internal queueing of commands
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(typically NCQ), device idling happens to be always detrimental
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for throughput. So, with these devices, BFQ performs idling
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to throughput. So, with these devices, BFQ performs idling
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only when strictly needed for service guarantees, i.e., for
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guaranteeing low latency or fairness. In these cases, overall
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throughput may be sub-optimal. No solution currently exists to
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@ -212,7 +212,7 @@ plus a lot of code, are borrowed from CFQ.
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and to reduce their latency. The most important action taken to
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achieve this goal is to give to the queues associated with these
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applications more than their fair share of the device
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throughput. For brevity, we call just "weight-raising" the whole
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throughput. For brevity, we call it just "weight-raising" the whole
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sets of actions taken by BFQ to privilege these queues. In
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particular, BFQ provides a milder form of weight-raising for
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interactive applications, and a stronger form for soft real-time
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@ -231,7 +231,7 @@ plus a lot of code, are borrowed from CFQ.
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responsive in detecting interleaved I/O (cooperating processes),
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that it enables BFQ to achieve a high throughput, by queue
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merging, even for queues for which CFQ needs a different
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mechanism, preemption, to get a high throughput. As such EQM is a
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mechanism, preemption, to get a high throughput. As such, EQM is a
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unified mechanism to achieve a high throughput with interleaved
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I/O.
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@ -254,7 +254,7 @@ plus a lot of code, are borrowed from CFQ.
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- First, with any proportional-share scheduler, the maximum
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deviation with respect to an ideal service is proportional to
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the maximum budget (slice) assigned to queues. As a consequence,
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BFQ can keep this deviation tight not only because of the
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BFQ can keep this deviation tight, not only because of the
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accurate service of B-WF2Q+, but also because BFQ *does not*
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need to assign a larger budget to a queue to let the queue
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receive a higher fraction of the device throughput.
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@ -327,7 +327,7 @@ applications. Unset this tunable if you need/want to control weights.
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slice_idle
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----------
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This parameter specifies how long BFQ should idle for next I/O
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This parameter specifies how long BFQ should idle for the next I/O
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request, when certain sync BFQ queues become empty. By default
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slice_idle is a non-zero value. Idling has a double purpose: boosting
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throughput and making sure that the desired throughput distribution is
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@ -365,7 +365,7 @@ terms of I/O-request dispatches. To guarantee that the actual service
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order then corresponds to the dispatch order, the strict_guarantees
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tunable must be set too.
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There is an important flipside for idling: apart from the above cases
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There is an important flip side to idling: apart from the above cases
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where it is beneficial also for throughput, idling can severely impact
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throughput. One important case is random workload. Because of this
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issue, BFQ tends to avoid idling as much as possible, when it is not
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@ -475,7 +475,7 @@ max_budget
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Maximum amount of service, measured in sectors, that can be provided
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to a BFQ queue once it is set in service (of course within the limits
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of the above timeout). According to what said in the description of
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of the above timeout). According to what was said in the description of
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the algorithm, larger values increase the throughput in proportion to
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the percentage of sequential I/O requests issued. The price of larger
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values is that they coarsen the granularity of short-term bandwidth
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