Bug 20948 - bcache: call force_wake_up_gc() if necessary in check_should_bypass()
Summary: bcache: call force_wake_up_gc() if necessary in check_should_bypass()
Status: NEW
Alias: None
Product: ANCK 5.10 Dev
Classification: ANCK
Component: drivers (show other bugs) drivers
Version: 5.10.y-19
Hardware: All Linux
: P3-Medium S3-normal
Target Milestone: ---
Assignee: GuixinLiu
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Reported: 2025-05-13 11:08 UTC by geshifei
Modified: 2025-05-13 11:08 UTC (History)
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Description geshifei 2025-05-13 11:08:48 UTC 
Description of problem:
高负载io场景，bcache

Version-Release number of selected component (if applicable):
无

How reproducible:
大负载压测

Steps to Reproduce:
1，设置bcache模块参数
   bcache bch_cutoff_writeback=70
  bch_cutoff_writeback_sync=90
2，fio按读写比例6:4压测
3，测试完成后，间隔一段时间执行cat /sys/block/bcache*/bcache/cache/cache_available_percent，查看是否会变大

Actual results:
部分bcache盘的cache_available_percent一直是4%，这会导致测试一轮后，bcache盘的可用空间只有nvme盘的4%

Expected results:
cache_available_percent应该随着时间递增而变大

Additional info:
这是bcache的一个bug，见kernel upstrem的提交 05356938a4be356adde4eab4425c6822f3c7d706