[MINOR] KmsgWriter opens /dev/kmsg on every write #31

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opened 2026-05-11 10:52:02 +00:00 by thabeta · 1 comment

thabeta commented

2026-05-11 10:52:02 +00:00

Owner

Problem

KmsgWriter::write in my_init_pid1 opens /dev/kmsg for every single log write. This is slow and could fail under resource pressure during early boot when FDs are scarce.

Impact

Performance degradation during boot. Potential log loss if /dev/kmsg open fails during resource exhaustion.

Files

crates/my_init_pid1/src/main.rs -- KmsgWriter struct

Suggested Fix

Open /dev/kmsg once during init and reuse the file descriptor. Store it as a static or in the writer struct.

## Problem `KmsgWriter::write` in `my_init_pid1` opens `/dev/kmsg` for every single log write. This is slow and could fail under resource pressure during early boot when FDs are scarce. ## Impact Performance degradation during boot. Potential log loss if `/dev/kmsg` open fails during resource exhaustion. ## Files - `crates/my_init_pid1/src/main.rs` -- `KmsgWriter` struct ## Suggested Fix Open `/dev/kmsg` once during init and reuse the file descriptor. Store it as a static or in the writer struct.

thabeta added the

enhancement

label

2026-05-11 10:53:00 +00:00

salmaelsoly commented

2026-05-11 13:36:08 +00:00

Member

Classification: valid-bug — KmsgWriter opens /dev/kmsg on every write instead of caching the FD, causing performance degradation during early boot.

Per issue description referencing crates/my_init_pid1/src/main.rs: open /dev/kmsg per write is slow and could fail under FD scarcity.

> Classification: valid-bug — KmsgWriter opens /dev/kmsg on every write instead of caching the FD, causing performance degradation during early boot. Per issue description referencing crates/my_init_pid1/src/main.rs: open /dev/kmsg per write is slow and could fail under FD scarcity.