This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

GNU C Library master sources branch master updated. glibc-2.26.9000-717-g6d58ce5

This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".

The branch, master has been updated
       via  6d58ce5e5072945d44f2dba83ad16cd6febd056c (commit)
      from  659ca267360e1c1f64eea9205bb81cb5e9049908 (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------;a=commitdiff;h=6d58ce5e5072945d44f2dba83ad16cd6febd056c

commit 6d58ce5e5072945d44f2dba83ad16cd6febd056c
Author: Richard Henderson <>
Date:   Fri Nov 3 16:38:16 2017 +0000

    aarch64: Guess L1 cache linesize for aarch64
    Using the cache hierarchy linesize minimum in CTR_EL0.
    See the comment within the code for rationale.
    	* sysdeps/unix/sysv/linux/aarch64/sysconf.c: New file.

diff --git a/ChangeLog b/ChangeLog
index e1146ba..d0ef94c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2017-11-03  Richard Henderson  <>
+	* sysdeps/unix/sysv/linux/aarch64/sysconf.c: New file.
 2017-11-03  Szabolcs Nagy  <>
 	* sysdeps/aarch64/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Optimize.
diff --git a/sysdeps/unix/sysv/linux/aarch64/sysconf.c b/sysdeps/unix/sysv/linux/aarch64/sysconf.c
new file mode 100644
index 0000000..30608dd
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/sysconf.c
@@ -0,0 +1,55 @@
+/* Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   Lesser General Public License for more details.
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <>.  */
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+static long int linux_sysconf (int name);
+/* Get the value of the system variable NAME.  */
+long int
+__sysconf (int name)
+  unsigned ctr;
+  /* Unfortunately, the registers that contain the actual cache info
+     (CCSIDR_EL1, CLIDR_EL1, and CSSELR_EL1) are protected by the Linux
+     kernel (though they need not have been).  However, CTR_EL0 contains
+     the *minimum* linesize in the entire cache hierarchy, and is
+     accessible to userland, for use in __aarch64_sync_cache_range,
+     and it is a reasonable assumption that the L1 cache will have that
+     minimum line size.  */
+  switch (name)
+    {
+      asm("mrs\t%0, ctr_el0" : "=r"(ctr));
+      return 4 << (ctr & 0xf);
+      asm("mrs\t%0, ctr_el0" : "=r"(ctr));
+      return 4 << ((ctr >> 16) & 0xf);
+    }
+  return linux_sysconf (name);
+/* Now the generic Linux version.  */
+#undef __sysconf
+#define __sysconf static linux_sysconf
+#include <sysdeps/unix/sysv/linux/sysconf.c>


Summary of changes:
 ChangeLog                                          |    4 +++
 sysdeps/unix/sysv/linux/{x86 => aarch64}/sysconf.c |   29 ++++++++++++++-----
 2 files changed, 25 insertions(+), 8 deletions(-)
 copy sysdeps/unix/sysv/linux/{x86 => aarch64}/sysconf.c (53%)

GNU C Library master sources

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]