From: Carlos O'Donell <carlos@redhat.com>
To: Konstantin Kharlamov <hi-angel@yandex.ru>,
Christian Hoff <christian_hoff@gmx.net>,
libc-help@sourceware.org
Subject: Re: Excessive memory consumption when using malloc()
Date: Thu, 25 Nov 2021 13:21:25 -0500 [thread overview]
Message-ID: <c20fabf9-3eb1-3f06-47a3-20da3ddc8e25@redhat.com> (raw)
In-Reply-To: <56522c8f847ddd27fdffedecb516f778837f9e92.camel@yandex.ru>
On 11/25/21 13:12, Konstantin Kharlamov via Libc-help wrote:
> So there you go, you 10G of unreleased memory is a Glibc feature, no complaints
> ;-P
Freeing memory back to the OS is a form of cache invalidation, and cache
invalidation is hard and workload dependent.
In this specific case, particularly with 50MiB, you are within the 64MiB
64-bit process heap size, and the 1024-byte frees do not trigger the
performance expensive consolidation and heap reduction (which requires
a munmap syscall to release the resources).
In the case of 10GiB, and 512KiB allocations, we are talking different
behaviour. I have responded here with my recommendations:
https://sourceware.org/pipermail/libc-help/2021-November/006052.html
--
Cheers,
Carlos.
next prev parent reply other threads:[~2021-11-25 18:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-25 17:20 Christian Hoff
2021-11-25 17:46 ` Konstantin Kharlamov
2021-11-25 18:12 ` Konstantin Kharlamov
2021-11-25 18:21 ` Carlos O'Donell [this message]
2021-11-25 20:56 ` Adhemerval Zanella
2021-11-26 18:10 ` Christian Hoff
2021-11-29 17:06 ` Patrick McGehearty
2021-11-25 18:20 ` Carlos O'Donell
2021-11-26 17:58 ` Christian Hoff
2021-11-29 19:44 ` Christian Hoff
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