malloc: Use __get_nprocs on arena_get2 (BZ 30945)

backport from upstream 506e47da1d

Signed-off-by: Lu Jingxiao <lujingxiao@huawei.com>

glibc.spec

@@ -67,7 +67,7 @@
 ##############################################################################
 Name: 	 	glibc
 Version: 	2.38
-Release: 	21
+Release: 	22
 Summary: 	The GNU libc libraries
 License:	%{all_license}
 URL: 		http://www.gnu.org/software/glibc/
@@ -140,6 +140,7 @@ Patch51: sparc64-Remove-unwind-information-from-signal-return.patch
 Patch52: sparc-Fix-sparc64-memmove-length-comparison-BZ-31266.patch
 Patch53: sparc-Remove-unwind-information-from-signal-return-s.patch
 Patch54: arm-Remove-wrong-ldr-from-_dl_start_user-BZ-31339.patch
+Patch55: malloc-Use-__get_nprocs-on-arena_get2-BZ-30945.patch
 
 Patch9000: turn-default-value-of-x86_rep_stosb_threshold_form_2K_to_1M.patch
 Patch9001: locale-delete-no-hard-link-to-avoid-all_language-pac.patch 
@@ -1353,6 +1354,9 @@ fi
 %endif
 
 %changelog
+* Fri Feb 23 Jingxiao Lu <lujingxiao@huawei.com> - 2.38-22
+- malloc: Use __get_nprocs on arena_get2 (BZ 30945)
+
 * Tue Feb 6 Qingqing Li <liqingqing3@huawei.com> - 2.38-21
 - arm: Remove wrong ldr from _dl_start_user (BZ 31339)
 

malloc-Use-__get_nprocs-on-arena_get2-BZ-30945.patch

@@ -0,0 +1,92 @@
+From 0ba0f3c749211d2888ee310b2b58ff6401eae624 Mon Sep 17 00:00:00 2001
+From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
+Date: Wed, 11 Oct 2023 13:43:56 -0300
+Subject: [PATCH] malloc: Use __get_nprocs on arena_get2 (BZ 30945)
+
+This restore the 2.33 semantic for arena_get2.  It was changed by
+11a02b035b46 to avoid arena_get2 call malloc (back when __get_nproc
+was refactored to use an scratch_buffer - 903bc7dcc2acafc).  The
+__get_nproc was refactored over then and now it also avoid to call
+malloc.
+
+The 11a02b035b46 did not take in consideration any performance
+implication, which should have been discussed properly.  The
+__get_nprocs_sched is still used as a fallback mechanism if procfs
+and sysfs is not acessible.
+
+Checked on x86_64-linux-gnu.
+Reviewed-by: DJ Delorie <dj@redhat.com>
+
+(cherry picked from commit 472894d2cfee5751b44c0aaa71ed87df81c8e62e)
+---
+ include/sys/sysinfo.h                 | 4 ----
+ misc/getsysstats.c                    | 6 ------
+ sysdeps/mach/getsysstats.c            | 6 ------
+ sysdeps/unix/sysv/linux/getsysstats.c | 2 +-
+ 4 files changed, 1 insertion(+), 17 deletions(-)
+
+diff --git a/include/sys/sysinfo.h b/include/sys/sysinfo.h
+index c490561581..65742b1036 100644
+--- a/include/sys/sysinfo.h
++++ b/include/sys/sysinfo.h
+@@ -14,10 +14,6 @@ libc_hidden_proto (__get_nprocs_conf)
+ extern int __get_nprocs (void);
+ libc_hidden_proto (__get_nprocs)
+ 
+-/* Return the number of available processors which the process can
+-   be scheduled.  */
+-extern int __get_nprocs_sched (void) attribute_hidden;
+-
+ /* Return number of physical pages of memory in the system.  */
+ extern long int __get_phys_pages (void);
+ libc_hidden_proto (__get_phys_pages)
+diff --git a/misc/getsysstats.c b/misc/getsysstats.c
+index 5f36adc0e8..23cc112074 100644
+--- a/misc/getsysstats.c
++++ b/misc/getsysstats.c
+@@ -44,12 +44,6 @@ weak_alias (__get_nprocs, get_nprocs)
+ link_warning (get_nprocs, "warning: get_nprocs will always return 1")
+ 
+ 
+-int
+-__get_nprocs_sched (void)
+-{
+-  return 1;
+-}
+-
+ long int
+ __get_phys_pages (void)
+ {
+diff --git a/sysdeps/mach/getsysstats.c b/sysdeps/mach/getsysstats.c
+index 5184e5eee1..d3834f3b69 100644
+--- a/sysdeps/mach/getsysstats.c
++++ b/sysdeps/mach/getsysstats.c
+@@ -62,12 +62,6 @@ __get_nprocs (void)
+ libc_hidden_def (__get_nprocs)
+ weak_alias (__get_nprocs, get_nprocs)
+ 
+-int
+-__get_nprocs_sched (void)
+-{
+-  return __get_nprocs ();
+-}
+-
+ /* Return the number of physical pages on the system. */
+ long int
+ __get_phys_pages (void)
+diff --git a/sysdeps/unix/sysv/linux/getsysstats.c b/sysdeps/unix/sysv/linux/getsysstats.c
+index b0b6c154ac..1ea7f1f01f 100644
+--- a/sysdeps/unix/sysv/linux/getsysstats.c
++++ b/sysdeps/unix/sysv/linux/getsysstats.c
+@@ -29,7 +29,7 @@
+ #include <sys/sysinfo.h>
+ #include <sysdep.h>
+ 
+-int
++static int
+ __get_nprocs_sched (void)
+ {
+   enum
+-- 
+2.23.0
+