From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 3BE9B6B0038 for ; Wed, 1 Mar 2017 06:30:03 -0500 (EST) Received: by mail-wr0-f199.google.com with SMTP id u108so3194702wrb.3 for ; Wed, 01 Mar 2017 03:30:03 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id r5si625112wmr.74.2017.03.01.03.30.01 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 01 Mar 2017 03:30:02 -0800 (PST) From: Nikolay Borisov Subject: [PATCH v3] lockdep: Teach lockdep about memalloc_noio_save Date: Wed, 1 Mar 2017 13:29:57 +0200 Message-Id: <1488367797-27278-1-git-send-email-nborisov@suse.com> Sender: owner-linux-mm@kvack.org List-ID: To: peterz@infradead.org Cc: linux-kernel@vger.kernel.org, mhocko@kernel.org, vbabka.lkml@gmail.com, linux-mm@kvack.org, mingo@redhat.com, Nikolay Borisov Commit 21caf2fc1931 ("mm: teach mm by current context info to not do I/O during memory allocation") added the memalloc_noio_(save|restore) functions to enable people to modify the MM behavior by disbaling I/O during memory allocation. This was further extended in Fixes: 934f3072c17c ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set"). memalloc_noio_* functions prevent allocation paths recursing back into the filesystem without explicitly changing the flags for every allocation site. However, lockdep hasn't been keeping up with the changes and it entirely misses handling the memalloc_noio adjustments. Instead, it is left to the callers of __lockdep_trace_alloc to call the functino after they have shaven the respective GFP flags. Let's fix this by making lockdep explicitly do the shaving of respective GFP flags. Fixes: 934f3072c17c ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set") Signed-off-by: Nikolay Borisov --- kernel/locking/lockdep.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) Changes since v2: * Incorporate Michal's suggestion of using memalloc_noio_flags explicitly. * Tune the commit message to make the problem statement a bit more descriptive. diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 9812e5dd409e..565506c9e99c 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2861,6 +2861,8 @@ static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags) if (unlikely(!debug_locks)) return; + gfp_mask = memalloc_noio_flags(gfp_mask); + /* no reclaim without waiting on it */ if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) return; @@ -3852,7 +3854,7 @@ EXPORT_SYMBOL_GPL(lock_unpin_lock); void lockdep_set_current_reclaim_state(gfp_t gfp_mask) { - current->lockdep_reclaim_gfp = gfp_mask; + current->lockdep_reclaim_gfp = memalloc_noio_flags(gfp_mask); } void lockdep_clear_current_reclaim_state(void) -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org