kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K

kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K

BugLink: https://bugs.launchpad.net/bugs/1848047
[ Upstream commit b751c52bb587ae66f773b15204ef7a147467f4c7 ]

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).

Link: http://lkml.kernel.org/r/20190730154027.101525-1-drinkcat@chromium.org
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>