Received-SPF: pass (google.com: domain of linux-kernel+bounces-191569-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
From: Ankur Arora <ankur.a.arora@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org,
        paulmck@kernel.org, rostedt@goodmis.org, mark.rutland@arm.com,
        juri.lelli@redhat.com, joel@joelfernandes.org, raghavendra.kt@amd.com,
        sshegde@linux.ibm.com, boris.ostrovsky@oracle.com,
        konrad.wilk@oracle.com, Ankur Arora <ankur.a.arora@oracle.com>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>
Subject: [PATCH v2 19/35] x86/thread_info: define TIF_NEED_RESCHED_LAZY
Date: Mon, 27 May 2024 17:35:05 -0700
Message-Id: <20240528003521.979836-20-ankur.a.arora@oracle.com>
In-Reply-To: <20240528003521.979836-1-ankur.a.arora@oracle.com>
References: <20240528003521.979836-1-ankur.a.arora@oracle.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: 
	=?us-ascii?Q?3A7YWcTJezE+Jn726fVD0yYmDZAXlxzdMGghiG+cStc0xKY0UrnU1Cs0wZsb?=
 =?us-ascii?Q?l4nFRJCDY2t0+yOSYccurnhBXp7cTR8Gn0ghd0bO8AFGqk3vAr4FxvszSbtH?=
 =?us-ascii?Q?WexsVaEKeztQra0OGmuni4PdgekhVwdh9JEurJolhguekeatLvCGcEPH0Lr3?=
 =?us-ascii?Q?b2/gYfhJCvpjXTDkmq8WChjiNXLM61/cZwL4V3W5b1LX9xG8R3ro89cylshe?=
 =?us-ascii?Q?Z/EXQv8ViHZf8T1mW8MvGFUIc49F2hxo3OKMj7wXFBgSxq3CMqPfmCbIjUha?=
 =?us-ascii?Q?mwFrVBMUiKwsA0J+8fcw/QgwvJbqoRHFvbprMxPlFEiVOrx5sBgrc11If2OI?=
 =?us-ascii?Q?TagCIHA6fXUXBU0bkGUyBhMKsvmi0Vx77B5b8ZI1m6csQDCM4JJSOhNdOqjg?=
 =?us-ascii?Q?FnCJwDBqoDThxvrxOlkx05C8MTDAtP0pmb7UouactBGvUEOO7Ld70g5Cbc5W?=
 =?us-ascii?Q?1oq+JB/h6Xos7UnbCNeew2u7L+BIoz4dTqnorebhy/ciygfP2Gn7caFFa03z?=
 =?us-ascii?Q?4IIJPBeupk5OxZiunVzE9iuymzsrc13R3EeC98t1y+QQdspYwSEmeMGHupX9?=
 =?us-ascii?Q?dz2+rOO4A1q1t4fHeJ+pz3XNBBLN1OVjTQZhKikNT///RvwA8TDx9bYOmsh+?=
 =?us-ascii?Q?KL91Vq7rpH+HJAlsYGn67HyCMjmAnHU6/AHg/83mN/QJy8Mtu8DWlKaFOv96?=
 =?us-ascii?Q?ql7Qo5i5xY5nlW99mOfQ8dRbk//RRbASIAnfQHDVWHm560SsBq3tsuQhXwLb?=
 =?us-ascii?Q?EZmldL7fCEaPs7YGMr22zyJOiJ05sMRVsoNKnq/YtolHbDZqZKJR2tbAHTWb?=
 =?us-ascii?Q?gacSevknkFVkbkvB7UXSvOkQWI+bRMl7g1EBA7sDRWknlZ3ZGcNm9oUuxwjC?=
 =?us-ascii?Q?bfi21Dlyg21GM5scz8xcNvuSlcHW15dXjIi9JcWBfioR0Ts0sJLNcvff9WnU?=
 =?us-ascii?Q?tfh3HZKZbbjiXs4KiYSzllmhGhVvwQKkFMJSDcJP5WL2DQcHsQU12aahWJU3?=
 =?us-ascii?Q?Ffzek0rk0XIGcEnrweq+YGzFDUuna3xiqxSrIt8tqLkn6BkUJC+5oLjAK5FK?=
 =?us-ascii?Q?AyWzSeoGaw9Eqb+rPqoqtwWirrZeYEKu8a/TS85DLJMDtKlPGtT41KmsqpQT?=
 =?us-ascii?Q?Zo+D2sjCnqhGzJjTU3CeD8cVDL57KzSz0eiR9rssj6ynmRyfMiw+XOkbwKij?=
 =?us-ascii?Q?LAtIRRlNatafbwsnH1XpqYSaUOZxS2lKpfTVrLn7Z13cdzhQdRI3EaWBEBN+?=
 =?us-ascii?Q?onnwcrUqWj5N1f+J1GcH3YkqJOuVmN6x7SIeT8YDB6RJ/oLYeYTEB2LunmZI?=
 =?us-ascii?Q?wIJuMFJUAt/bpo7+8wVNW54gdzHWf5BbIO2EW8/B7z7PHsSPJhGtBmPlVrSh?=
 =?us-ascii?Q?l++p0kVi/V0V2Dq3gMmkKoXYArCjMg3StwbgtVWfxt6zH4+rEfBCc4cZmUY8?=
 =?us-ascii?Q?eWvreMOY7CSceexr903fiN7L4zbQKr2lgLM9bdsHdbDcy6OH3yPJJZMQsgrH?=
 =?us-ascii?Q?JQ2V6JiWLQfgnBGWhSIm33dYQejfIh75kuSf0UJqbkaR4ARCYP51FXFCmks5?=
 =?us-ascii?Q?OhxaJgiyNENHOiDSLKbxmh0IqzBdYXc4K8ky21eOlVYrbjp0bwsJ8ImvRUVJ?=
 =?us-ascii?Q?3w=3D=3D?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 
	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
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 9e4ae77c-402e-4da7-9c8a-08dc7eae34aa
X-MS-Exchange-CrossTenant-AuthSource: CO6PR10MB5409.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 May 2024 00:36:25.3805
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 98meQNBRclPEnlvnzA6359Ix8lGoPir2YJAwgfFD6kmENEG/EOSEJ7TWK3rQbn/Knd94cgd3nSwsTM91coo8sF+vSG1s3XEDHpQP2Mq/PmE=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR10MB7177
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.650,FMLib:17.12.28.16
 definitions=2024-05-27_06,2024-05-27_01,2024-05-17_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 spamscore=0 suspectscore=0
 adultscore=0 phishscore=0 malwarescore=0 mlxlogscore=963 bulkscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2405010000
 definitions=main-2405280003
X-Proofpoint-GUID: K61TMizPoC3S0Ti_SYsMJsUB7gsJHRV4
X-Proofpoint-ORIG-GUID: K61TMizPoC3S0Ti_SYsMJsUB7gsJHRV4

Define TIF_NEED_RESCHED_LAZY which, with TIF_NEED_RESCHED provides the
scheduler with two kinds of rescheduling intent: TIF_NEED_RESCHED,
for the usual rescheduling at the next safe preemption point;
TIF_NEED_RESCHED_LAZY expressing an intent to reschedule at some
time in the future while allowing the current task to run to
completion.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/87jzshhexi.ffs@tglx/
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
---
 arch/x86/Kconfig                   | 1 +
 arch/x86/include/asm/thread_info.h | 6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 928820e61cb5..5cd83b12f6fd 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -277,6 +277,7 @@ config X86
 	select HAVE_STATIC_CALL
 	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
 	select HAVE_PREEMPT_DYNAMIC_CALL
+	select HAVE_PREEMPT_AUTO
 	select HAVE_RSEQ
 	select HAVE_RUST			if X86_64
 	select HAVE_SYSCALL_TRACEPOINTS
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 12da7dfd5ef1..6862bbbb98ab 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -87,8 +87,9 @@ struct thread_info {
 #define TIF_NOTIFY_RESUME	1	/* callback before returning to user */
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
-#define TIF_SINGLESTEP		4	/* reenable singlestep on user return*/
-#define TIF_SSBD		5	/* Speculative store bypass disable */
+#define TIF_NEED_RESCHED_LAZY	4	/* Lazy rescheduling */
+#define TIF_SINGLESTEP		5	/* reenable singlestep on user return*/
+#define TIF_SSBD		6	/* Speculative store bypass disable */
 #define TIF_SPEC_IB		9	/* Indirect branch speculation mitigation */
 #define TIF_SPEC_L1D_FLUSH	10	/* Flush L1D on mm switches (processes) */
 #define TIF_USER_RETURN_NOTIFY	11	/* notify kernel of userspace return */
@@ -110,6 +111,7 @@ struct thread_info {
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
 #define _TIF_SSBD		(1 << TIF_SSBD)
 #define _TIF_SPEC_IB		(1 << TIF_SPEC_IB)
-- 
2.31.1