From 35b18b2725737d21a7fa97cf37d3db91cdf7aeff Mon Sep 17 00:00:00 2001 From: Jonas Schievink Date: Thu, 10 Jun 2021 14:58:52 +0200 Subject: Add support for mallinfo2 on glibc Linux --- crates/profile/src/memory_usage.rs | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) (limited to 'crates/profile/src') diff --git a/crates/profile/src/memory_usage.rs b/crates/profile/src/memory_usage.rs index 6ef58c9c1..0b0a196ae 100644 --- a/crates/profile/src/memory_usage.rs +++ b/crates/profile/src/memory_usage.rs @@ -32,9 +32,7 @@ impl MemoryUsage { allocated: Bytes(jemalloc_ctl::stats::allocated::read().unwrap() as isize), } } else if #[cfg(all(target_os = "linux", target_env = "gnu"))] { - // Note: This is incredibly slow. - let alloc = unsafe { libc::mallinfo() }.uordblks as isize; - MemoryUsage { allocated: Bytes(alloc) } + memusage_linux() } else if #[cfg(windows)] { // There doesn't seem to be an API for determining heap usage, so we try to // approximate that by using the Commit Charge value. @@ -58,6 +56,37 @@ impl MemoryUsage { } } +#[cfg(all(target_os = "linux", target_env = "gnu"))] +fn memusage_linux() -> MemoryUsage { + // Linux/glibc has 2 APIs for allocator introspection that we can use: mallinfo and mallinfo2. + // mallinfo uses `int` fields and cannot handle memory usage exceeding 2 GB. + // mallinfo2 is very recent, so its presence needs to be detected at runtime. + // Both are abysmally slow. + + use std::ffi::CStr; + use std::sync::atomic::{AtomicUsize, Ordering}; + + static MALLINFO2: AtomicUsize = AtomicUsize::new(1); + + let mut mallinfo2 = MALLINFO2.load(Ordering::Relaxed); + if mallinfo2 == 1 { + let cstr = CStr::from_bytes_with_nul(b"mallinfo2\0").unwrap(); + mallinfo2 = unsafe { libc::dlsym(libc::RTLD_DEFAULT, cstr.as_ptr()) } as usize; + // NB: races don't matter here, since they'll always store the same value + MALLINFO2.store(mallinfo2, Ordering::Relaxed); + } + + if mallinfo2 == 0 { + // mallinfo2 does not exist, use mallinfo. + let alloc = unsafe { libc::mallinfo() }.uordblks as isize; + MemoryUsage { allocated: Bytes(alloc) } + } else { + let mallinfo2: fn() -> libc::mallinfo2 = unsafe { std::mem::transmute(mallinfo2) }; + let alloc = mallinfo2().uordblks as isize; + MemoryUsage { allocated: Bytes(alloc) } + } +} + #[derive(Default, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)] pub struct Bytes(isize); -- cgit v1.2.3