From: Eric Wong <e@80x24.org>
To: mwrap-perl@80x24.org
Subject: [PATCH 2/2] increase DEFAULT_GRANULARITY to 64M
Date: Wed, 30 Nov 2022 06:49:30 +0000 [thread overview]
Message-ID: <20221130064930.5239-3-e@80x24.org> (raw)
In-Reply-To: <20221130064930.5239-1-e@80x24.org>
Since Linux maps are file-backed, it won't provide an increase
in physical memory. Using larger chunks reduces syscalls and
avoids hitting the Linux system-wide /proc/sys/vm/max_map_count
limit.
It's probably safe for all x86-64 systems these days, and 32-bit
is prone to overflow and not a target of this project (though
this project aims to make other projects suitable for
underpowered 32-bit systems).
---
mymalloc.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mymalloc.h b/mymalloc.h
index f5a171e..024075b 100644
--- a/mymalloc.h
+++ b/mymalloc.h
@@ -29,6 +29,9 @@
#include <fcntl.h>
#include <errno.h>
+/* this is fine on most x86-64, especially with file-backed mmap(2) */
+#define DEFAULT_GRANULARITY (64U * 1024U * 1024U)
+
#if !defined(MWRAP_FILE_BACKED) && defined(__linux__) && defined(O_TMPFILE)
# define MWRAP_FILE_BACKED 1
#else
next prev parent reply other threads:[~2022-11-30 6:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-30 6:49 [PATCH 0/2] support file-backed mmap on Linux Eric Wong
2022-11-30 6:49 ` [PATCH 1/2] use " Eric Wong
2022-11-30 20:43 ` Eric Wong
2022-11-30 6:49 ` Eric Wong [this message]
2022-11-30 21:08 ` [PATCH v2 0/2] support " Eric Wong
2022-11-30 21:08 ` [PATCH v2 1/2] use " Eric Wong
2022-12-02 10:14 ` Eric Wong
2022-11-30 21:08 ` [PATCH v2 2/2] increase DEFAULT_GRANULARITY to 64M Eric Wong
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