RFR: JDK-8324598: use mem_unit when working with sysinfo memory and swap related information

[David Holmes]

On Wed, 24 Jan 2024 10:07:17 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> According to the sysinfo manpage ( https://man7.org/linux/man-pages/man2/sysinfo.2.html ) the memory and swap related entries in the struct sysinfo are given as multiples of mem_unit bytes.
> "In the above structure, sizes of the memory and swap fields are given as multiples of mem_unit bytes."
> 
> This is considered in most parts of the OpenJDK codebase when sysinfo is used but not all; should be added where it is missing.

Looks fine.

Minor nit with lack of parentheses.

Thanks

src/hotspot/os/linux/os_linux.cpp line 420:

> 418:   struct sysinfo si;
> 419:   sysinfo(&si);
> 420:   return (julong)si.totalswap * si.mem_unit;

Suggestion: `(julong)(si.totalswap * si.mem_unit);

src/java.base/linux/native/libjava/CgroupMetrics.c line 57:

> 55:          return 0; // syinfo failed, treat as no swap
> 56:     }
> 57:     return (jlong)si.totalswap * si.mem_unit;

Suggestion: `(julong)(si.totalswap * si.mem_unit);

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Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17550#pullrequestreview-1842877781
PR Review Comment: https://git.openjdk.org/jdk/pull/17550#discussion_r1465868336
PR Review Comment: https://git.openjdk.org/jdk/pull/17550#discussion_r1465868493