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9f68eabab9
On 32-bit systems, the throughput calculation in
damos_set_effective_quota() is prone to unnecessary multiplication
overflow. Using mult_frac() to fix it.
Andrew Paniakin also recently found and privately reported this issue, on
64 bit systems. This can also happen on 64-bit systems, once the charged
size exceeds ~17 TiB. On systems running for long time in production,
this issue can actually happen.
More specifically, when a DAMOS scheme having the time quota run for
longtime, throughput calculation can overflow and set esz too small. As a
result, speed of the scheme get unexpectedly slow.
Link: https://lkml.kernel.org/r/20250821125555.3020951-1-yanquanmin1@huawei.com
Fixes:
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||
|---|---|---|
| .. | ||
| tests | ||
| core.c | ||
| Kconfig | ||
| lru_sort.c | ||
| Makefile | ||
| modules-common.c | ||
| modules-common.h | ||
| ops-common.c | ||
| ops-common.h | ||
| paddr.c | ||
| reclaim.c | ||
| stat.c | ||
| sysfs-common.c | ||
| sysfs-common.h | ||
| sysfs-schemes.c | ||
| sysfs.c | ||
| vaddr.c | ||