Add a sysinfo wrapper #922
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src/sys/sysinfo.rs
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| /// Current number of processes. | ||
| pub fn process_count(&self) -> u32 { |
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Any reason why you picked u32 instead of u16 here?
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The max. process count on x86-64 Linux doesn't fit in a u16. The default does, but PID_MAX_LIMIT doesn't.
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It's defined as a __u16 in the Linux header file and in libc. Maybe the kernel can support >65536 processes, but sysinfo can't.
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Oh, that's odd. I guess I can change it to use u16 then. Both the libc crate and man page use unsigned short though, which can technically be a u32.
src/sys/sysinfo.rs
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| /// Returns the amount of completely unused RAM in Bytes. | ||
| /// | ||
| /// "Unused" in this context means that the RAM in neither actively used by programs, nor by the |
src/sys/sysinfo.rs
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| fn scale_mem(&self, units: libc::c_ulong) -> u64 { | ||
| (units * self.0.mem_unit as libc::c_ulong) as u64 |
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Looks like this multiplication is overflowing on 32-bit architectures.
src/sys/sysinfo.rs
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| /// [See `sysinfo(2)`](http://man7.org/linux/man-pages/man2/sysinfo.2.html). | ||
| pub fn sysinfo() -> Result<SysInfo> { | ||
| let mut info: libc::sysinfo = unsafe { mem::uninitialized() }; | ||
| match unsafe { libc::sysinfo(&mut info) } { |
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This can be simplified to let res = libc::sysinfo(...); Errno::result(res)
src/sys/sysinfo.rs
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| /// Current number of processes. | ||
| pub fn process_count(&self) -> u32 { |
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It's defined as a __u16 in the Linux header file and in libc. Maybe the kernel can support >65536 processes, but sysinfo can't.
src/sys/sysinfo.rs
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| pub fn ram_unused(&self) -> u64 { | ||
| self.scale_mem(self.0.freeram) | ||
| } | ||
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| fn scale_mem(&self, units: libc::c_ulong) -> u64 { | ||
| (units * self.0.mem_unit as libc::c_ulong) as u64 | ||
| (units as u64 * self.0.mem_unit as u64) as u64 |
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The final "as u64" is superfluous.
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Ok, I'm satisfied. All it needs now is a squash. We can't squash ourselves, because we use bors. |
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bors r+ |
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👎 Rejected by code reviews |
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Silly me. I have to hit "approve" before telling bors to merge. bors r+ |
922: Add a sysinfo wrapper r=asomers a=jonas-schievink Closes #505 Returned values were also inspected manually to be correct. Co-authored-by: Jonas Schievink <[email protected]>
Closes #505
Returned values were also inspected manually to be correct.