From: Song Liu <song@kernel.org>
To: <linux-kernel@vger.kernel.org>, <live-patching@vger.kernel.org>
Cc: <mingo@redhat.com>, <peterz@infradead.org>,
<vincent.guittot@linaro.org>, <jpoimboe@redhat.com>,
<joe.lawrence@redhat.com>, <kernel-team@fb.com>,
Song Liu <song@kernel.org>
Subject: [RFC] sched,livepatch: call klp_try_switch_task in __cond_resched
Date: Sat, 7 May 2022 10:46:28 -0700 [thread overview]
Message-ID: <20220507174628.2086373-1-song@kernel.org> (raw)
Busy kernel threads may block the transition of livepatch. Call
klp_try_switch_task from __cond_resched to make the transition easier.
Signed-off-by: Song Liu <song@kernel.org>
---
include/linux/livepatch.h | 2 ++
kernel/livepatch/transition.c | 2 +-
kernel/sched/core.c | 3 +++
3 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
index 2614247a9781..a9209f62550a 100644
--- a/include/linux/livepatch.h
+++ b/include/linux/livepatch.h
@@ -236,6 +236,7 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs,
unsigned int symindex, unsigned int secindex,
const char *objname);
+bool klp_try_switch_task(struct task_struct *task);
#else /* !CONFIG_LIVEPATCH */
static inline int klp_module_coming(struct module *mod) { return 0; }
@@ -253,6 +254,7 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs,
return 0;
}
+bool klp_try_switch_task(struct task_struct *task) { return true; }
#endif /* CONFIG_LIVEPATCH */
#endif /* _LINUX_LIVEPATCH_H_ */
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index f6310f848f34..4257a8eec64b 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -278,7 +278,7 @@ static int klp_check_stack(struct task_struct *task, char *err_buf)
* running, or it's sleeping on a to-be-patched or to-be-unpatched function, or
* if the stack is unreliable, return false.
*/
-static bool klp_try_switch_task(struct task_struct *task)
+bool klp_try_switch_task(struct task_struct *task)
{
static char err_buf[STACK_ERR_BUF_SIZE];
struct rq *rq;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a7302b7b65f2..41d1c7a86912 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6990,6 +6990,9 @@ SYSCALL_DEFINE0(sched_yield)
#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
int __sched __cond_resched(void)
{
+ if (unlikely(klp_patch_pending(current)))
+ klp_try_switch_task(current);
+
if (should_resched(0)) {
preempt_schedule_common();
return 1;
--
2.30.2
next reply other threads:[~2022-05-07 17:46 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-07 17:46 Song Liu [this message]
2022-05-07 18:26 ` [RFC] sched,livepatch: call klp_try_switch_task in __cond_resched Rik van Riel
2022-05-07 19:04 ` Song Liu
2022-05-07 19:18 ` Rik van Riel
2022-05-08 20:41 ` Peter Zijlstra
2022-05-09 1:07 ` Rik van Riel
2022-05-09 7:04 ` Peter Zijlstra
2022-05-09 8:06 ` Song Liu
2022-05-09 9:38 ` Peter Zijlstra
2022-05-09 14:13 ` Rik van Riel
2022-05-09 15:22 ` Petr Mladek
2022-05-09 15:07 ` Petr Mladek
2022-05-09 16:22 ` Song Liu
2022-05-10 7:56 ` Petr Mladek
2022-05-10 13:33 ` Rik van Riel
2022-05-10 15:44 ` Petr Mladek
2022-05-10 16:07 ` Rik van Riel
2022-05-10 16:52 ` Josh Poimboeuf
2022-05-10 18:07 ` Rik van Riel
2022-05-10 18:42 ` Josh Poimboeuf
2022-05-10 19:45 ` Song Liu
2022-05-10 23:04 ` Josh Poimboeuf
2022-05-10 23:57 ` Song Liu
2022-05-11 0:33 ` Josh Poimboeuf
2022-05-11 9:24 ` Petr Mladek
2022-05-11 16:33 ` Song Liu
2022-05-12 4:07 ` Josh Poimboeuf
2022-05-13 12:33 ` Petr Mladek
2022-05-13 13:34 ` Peter Zijlstra
2022-05-11 0:35 ` Rik van Riel
2022-05-11 0:37 ` Josh Poimboeuf
2022-05-11 0:46 ` Rik van Riel
2022-05-11 1:12 ` Josh Poimboeuf
2022-05-11 18:09 ` Rik van Riel
2022-05-12 3:59 ` Josh Poimboeuf
2022-05-09 15:52 ` [RFC] sched,livepatch: call stop_one_cpu in klp_check_and_switch_task Rik van Riel
2022-05-09 16:28 ` Song Liu
2022-05-09 18:00 ` Josh Poimboeuf
2022-05-09 19:10 ` Rik van Riel
2022-05-09 19:17 ` Josh Poimboeuf
2022-05-09 19:49 ` Rik van Riel
2022-05-09 20:09 ` Josh Poimboeuf
2022-05-10 0:32 ` Song Liu
2022-05-10 9:35 ` Peter Zijlstra
2022-05-10 1:48 ` Rik van Riel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220507174628.2086373-1-song@kernel.org \
--to=song@kernel.org \
--cc=joe.lawrence@redhat.com \
--cc=jpoimboe@redhat.com \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=live-patching@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=vincent.guittot@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).