From 7878c231dae05bae9dcf2ad4d309f02e51625033 Mon Sep 17 00:00:00 2001 From: Qian Cai Date: Thu, 16 May 2019 15:57:41 -0400 Subject: slab: remove /proc/slab_allocators It turned out that DEBUG_SLAB_LEAK is still broken even after recent recue efforts that when there is a large number of objects like kmemleak_object which is normal on a debug kernel, # grep kmemleak /proc/slabinfo kmemleak_object 2243606 3436210 ... reading /proc/slab_allocators could easily loop forever while processing the kmemleak_object cache and any additional freeing or allocating objects will trigger a reprocessing. To make a situation worse, soft-lockups could easily happen in this sitatuion which will call printk() to allocate more kmemleak objects to guarantee an infinite loop. Also, since it seems no one had noticed when it was totally broken more than 2-year ago - see the commit fcf88917dd43 ("slab: fix a crash by reading /proc/slab_allocators"), probably nobody cares about it anymore due to the decline of the SLAB. Just remove it entirely. Suggested-by: Vlastimil Babka Suggested-by: Linus Torvalds Signed-off-by: Qian Cai Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 4 ---- 1 file changed, 4 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index fdfa173651eb..eae43952902e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -542,10 +542,6 @@ config DEBUG_SLAB allocation as well as poisoning memory on free to catch use of freed memory. This can make kmalloc/kfree-intensive workloads much slower. -config DEBUG_SLAB_LEAK - bool "Memory leak debugging" - depends on DEBUG_SLAB - config SLUB_DEBUG_ON bool "SLUB debugging on by default" depends on SLUB && SLUB_DEBUG -- cgit