[LU-19344] Performance regression due to file_read_confine_iter added

• Type: Bug
• Resolution: Unresolved
• Priority: Medium
• Severity: 3
• Assignee: Shaun Tancheff
• Reporter: Shaun Tancheff

Description

Added by ("LU-16025 llite: adjust read count as file got truncated") to handle read/truncate race.

The cl_io_init / cl_object_attr_get / cl_io_fini cost is excessive when reading from system cache.

• 4K reads are ~20% slower on fast_read() and ~5% on BIO

Maybe we can update attr only when truncate has been issued?

Issue Links

• is related to: LU-16025 Read past file size after truncate from another client