Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Nicolas Boichat <drinkcat@chromium.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Masahiro Yamada <yamada.masahiro@socionext.com>,
        Kees Cook <keescook@chromium.org>,
        Petr Mladek <pmladek@suse.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        Joe Lawrence <joe.lawrence@redhat.com>,
        Uladzislau Rezki <urezki@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-kernel@vger.kernel.org,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>
Subject: [PATCH] kmemleak: Increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K
Date:   Tue, 30 Jul 2019 23:40:27 +0800
Message-Id: <20190730154027.101525-1-drinkcat@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The current default value (400) is too low on many systems (e.g.
some ARM64 platform takes up 1000+ entries).

syzbot uses 16000 as default value, and has proved to be enough
on beefy configurations, so let's pick that value.

This consumes more RAM on boot (each entry is 160 bytes, so
in total ~2.5MB of RAM), but the memory would later be freed
(early_log is __initdata).

Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
---
 lib/Kconfig.debug | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index f567875b87657de..b5a24045ab13310 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -596,7 +596,7 @@ config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
 	int "Maximum kmemleak early log entries"
 	depends on DEBUG_KMEMLEAK
 	range 200 40000
-	default 400
+	default 16000
 	help
 	  Kmemleak must track all the memory allocations to avoid
 	  reporting false positives. Since memory may be allocated or
-- 
2.22.0.709.g102302147b-goog