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Rao" , linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Jinchao Wang Subject: [PATCH 11/17] mm/ksw: add self-debug functions for kstackwatch watch Date: Thu, 28 Aug 2025 15:32:44 +0800 Message-ID: <20250828073311.1116593-12-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250828073311.1116593-1-wangjinchao600@gmail.com> References: <20250828073311.1116593-1-wangjinchao600@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Introduce ksw_watch_show() and ksw_watch_fire() for runtime debugging of kstackwatch's watch mechanism: - ksw_watch_show(): prints the currently armed watch address and length - ksw_watch_fire(): forcibly triggers the watch by writing to the watched address These functions help validate the dynamic watch behavior and facilitate testing without requiring real events. Signed-off-by: Jinchao Wang --- mm/kstackwatch/kstackwatch.h | 2 ++ mm/kstackwatch/watch.c | 17 ++++++++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/mm/kstackwatch/kstackwatch.h b/mm/kstackwatch/kstackwatch.h index bc8664af4fa6..d1bb5ae75aae 100644 --- a/mm/kstackwatch/kstackwatch.h +++ b/mm/kstackwatch/kstackwatch.h @@ -47,5 +47,7 @@ int ksw_watch_init(struct ksw_config *config); void ksw_watch_exit(void); int ksw_watch_on(u64 watch_addr, u64 watch_len); void ksw_watch_off(void); +void ksw_watch_show(void); +void ksw_watch_fire(void); =20 #endif /* _KSTACKWATCH_H */ diff --git a/mm/kstackwatch/watch.c b/mm/kstackwatch/watch.c index 284facaac8fc..158843876958 100644 --- a/mm/kstackwatch/watch.c +++ b/mm/kstackwatch/watch.c @@ -118,7 +118,6 @@ int ksw_watch_on(u64 watch_addr, u64 watch_len) ksw_watch_on_local_cpu(&watch_info); } else { call_single_data_t *csd =3D &per_cpu(watch_csd, cpu); - smp_call_function_single_async(cpu, csd); } } @@ -160,3 +159,19 @@ void ksw_watch_exit(void) =20 pr_info("KSW: watch exited\n"); } + +/* self debug function */ +void ksw_watch_show(void) +{ + pr_info("KSW: watch target bp_addr: 0x%llx len:%llu\n", + watch_info.addr, watch_info.len); +} + +/* self debug function */ +void ksw_watch_fire(void) +{ + char *ptr =3D (char *)watch_info.addr; + + pr_warn("KSW: watch triggered immediately\n"); + *ptr =3D 0x42; // This should trigger immediately +} --=20 2.43.0