psi-util: fix error handling

Signed-off-by: zhaoxiaohu <zhaoxiaohu@kuaishou.com>

backport-psi-util-fix-error-handling.patch

@@ -0,0 +1,60 @@
+From 90ec8ebe33ec72ed6d9f451de9443d67dd351d72 Mon Sep 17 00:00:00 2001
+From: Lennart Poettering <lennart@poettering.net>
+Date: Mon, 27 Feb 2023 19:02:41 +0100
+Subject: [PATCH] psi-util: fix error handling
+
+We checked ERRNO_IS_NOT_SUPPORTED on a possible positive non-error code,
+which isn't right.
+
+Fix that. Also add caching, since we are about to call this more often.
+
+Reference: https://github.com/systemd/systemd/pull/26610/commits/1ea90a9d409999159345ad8e193f7ef4cc7f634d
+
+Signed-off-by: zhaoxiaohu <zhaoxiaohu@kuaishou.com>
+Signed-off-by: yuwang <yuwang@kuaishou.com>
+---
+ src/shared/psi-util.c | 23 ++++++++++++++---------
+ 1 file changed, 14 insertions(+), 9 deletions(-)
+
+diff --git a/src/shared/psi-util.c b/src/shared/psi-util.c
+index 009095e..9045ae2 100644
+--- a/src/shared/psi-util.c
++++ b/src/shared/psi-util.c
+@@ -106,20 +106,25 @@ int read_resource_pressure(const char *path, PressureType type, ResourcePressure
+ }
+ 
+ int is_pressure_supported(void) {
++        static thread_local int cached = -1;
+         const char *p;
++        int r;
+ 
+-        /* The pressure files, both under /proc and in cgroups, will exist
+-         * even if the kernel has PSI support disabled; we have to read
+-         * the file to make sure it doesn't return -EOPNOTSUPP */
+-        FOREACH_STRING(p, "/proc/pressure/cpu", "/proc/pressure/io", "/proc/pressure/memory") {
+-                int r;
++        /* The pressure files, both under /proc/ and in cgroups, will exist even if the kernel has PSI
++         * support disabled; we have to read the file to make sure it doesn't return -EOPNOTSUPP */
+ 
++        if (cached >= 0)
++                return cached;
++
++        FOREACH_STRING(p, "/proc/pressure/cpu", "/proc/pressure/io", "/proc/pressure/memory") {
+                 r = read_virtual_file(p, 0, NULL, NULL);
+-                if (r == -ENOENT || ERRNO_IS_NOT_SUPPORTED(r))
+-                        return 0;
+-                if (r < 0)
++                if (r < 0) {
++                        if (r == -ENOENT || ERRNO_IS_NOT_SUPPORTED(r))
++                                return (cached = false);
++
+                         return r;
++                }
+         }
+ 
+-        return 1;
++        return (cached = true);
+ }
+-- 
+2.33.0
+

systemd.spec

@@ -25,7 +25,7 @@
 Name:           systemd
 Url:            https://systemd.io/
 Version:        249
-Release:        92
+Release:        93
 License:        MIT and LGPLv2+ and GPLv2+
 Summary:        System and Service Manager
 
@@ -695,6 +695,7 @@ Patch6642:      backport-sysusers-insist-that-root-group-is-0.patch
 Patch6643:      backport-importd-Always-specify-file-unpacked-by-tar.patch
 Patch6644:      backport-docs-remove-dev-tty-confusion.patch
 Patch6645:      backport-wait-online-make-manager_link_is_online-return-0-whe.patch
+Patch6646:      backport-psi-util-fix-error-handling.patch
 
 Patch9001:      update-rtc-with-system-clock-when-shutdown.patch
 Patch9002:      udev-add-actions-while-rename-netif-failed.patch
@@ -2209,6 +2210,9 @@ grep -q -E '^KEYMAP="?fi-latin[19]"?' /etc/vconsole.conf 2>/dev/null &&
 /usr/bin/systemd-cryptenroll
 
 %changelog
+* Wed Dec 04 2024 zhangyao <zhangyao108@huawei.com> - 249-93
+- add backport-psi-util-fix-error-handling.patch
+
 * Wed Dec 04 2024 zhangyao <zhangyao108@huawei.com> - 249-92
 - wait-online: fix handling of unmanaged state
 - add backport-wait-online-make-manager_link_is_online-return-0-whe.patch