linux-kernel - Re: [PATCH] kmemleak: Report if we need to tune KMEMLEAK_EARLY_LOG

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Message-ID: <c248c83e-e9c1-6b4d-050e-9aa30cd14669@siemens.com>
Date:   Tue, 24 Apr 2018 18:10:14 +0200
From:   Jan Kiszka <jan.kiszka@...mens.com>
To:     Catalin Marinas <catalin.marinas@....com>
Cc:     "linux-mm@...ck.org" <linux-mm@...ck.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] kmemleak: Report if we need to tune
 KMEMLEAK_EARLY_LOG_SIZE

On 2018-04-24 17:55, Catalin Marinas wrote:
> On Tue, Apr 24, 2018 at 05:51:15PM +0200, Jan Kiszka wrote:
>> ...rather than just mysteriously disabling it.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
>> ---
>>  mm/kmemleak.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/mm/kmemleak.c b/mm/kmemleak.c
>> index 9a085d525bbc..156c0c69cc5c 100644
>> --- a/mm/kmemleak.c
>> +++ b/mm/kmemleak.c
>> @@ -863,6 +863,7 @@ static void __init log_early(int op_type, const void *ptr, size_t size,
>>  
>>  	if (crt_early_log >= ARRAY_SIZE(early_log)) {
>>  		crt_early_log++;
>> +		pr_warn("Too many early logs\n");
> 
> That's already printed, though later where we have an idea of how big the early
> log needs to be:
> 
> 	if (crt_early_log > ARRAY_SIZE(early_log))
> 		pr_warn("Early log buffer exceeded (%d), please increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n",
> 			crt_early_log);
> 

Well, that's good, but where you read "detector disabled", there is no
hint on that. I missed that because subsystems tend to not do any
further actions after telling they are off.

BTW, my system (virtual ARM64 target) required 26035 entries, which is a
few orders of magnitude above the default and pretty close the the
limit. What's causing this? Other debug options?

Jan

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