On 3/26/19 10:56 AM, Jakub Jelinek wrote:
> On Mon, Mar 25, 2019 at 09:42:01PM +0100, Jakub Jelinek wrote:
>> On Mon, Mar 25, 2019 at 03:10:04PM -0400, Jason Merrill wrote:
>>>> 2) has the false -> true fixed
>>>> 3) ditto, but furthermore is moved out of add_capture into the lambda
>>>> introducer parsing routine only, tests for [this, this] and [this, *this]
>>>> etc. are done using LAMBDA_EXPR_THIS_CAPTURE and the duplicate check for
>>>> capture_id is simplified too.
>>>
>>> I needed to make the below change to avoid crashing with
>>> --enable-gather-detailed-mem-stats, make sense? Incidentally, why not set
>>
>> CCing Martin on this, I really don't know how the mem-stats.h stuff is
>> supposed to work and how it works on reallocations.
>> Seems release_instance_overhead is used in expand method without the second
>> argument true and in the dtor with true, so the latter likely does both
>> what expand needs to do and undo what register_descriptor did.
>> And because register_descriptor has been called, it needs to be undone, but
>> as no register_instance_overhead has been called, that part should not be.
>> We don't have unregister_descriptor or something similar though.
>> So, the fix probably needs to add something in mem-stats.h and do what your
>> patch did + else if (m_gather_mem_stats) call this new mem_stat.h method
>> after the if (!Lazy || m_entries) block.
>
> Here is a patch that does that.
The patch is correct. Note that unregistering of a descriptor is not a critical,
but yes, it occupies a memory.
Martin
>
> Bootstrapped on x86_64-linux with --enable-gather-detailed-mem-stats,
> tested on a couple of lambda testcases with -fmem-report, some of them with
> zero or one explicit captures, on others with more of them (e.g. on
> lambda-init1{8,9}.C) and tested build without
> --enable-gather-detailed-mem-stats. Ok for trunk?
>
> 2019-03-26 Jason Merrill <ja...@redhat.com>
> Jakub Jelinek <ja...@redhat.com>
>
> * mem-stats.h (mem_alloc_description::unregister_descriptor): New
> method.
> (mem_alloc_description::release_object_overhead): Fix comment typos.
> * hash-table.h (hash_table::~hash_table): Call
> release_instance_overhead only if m_entries is non-NULL, otherwise
> call unregister_descriptor.
>
> --- gcc/mem-stats.h.jj 2019-02-26 21:35:28.959081094 +0100
> +++ gcc/mem-stats.h 2019-03-26 09:25:10.132128088 +0100
> @@ -342,9 +342,15 @@ public:
> T *release_instance_overhead (void *ptr, size_t size,
> bool remove_from_map = false);
>
> - /* Release intance object identified by PTR pointer. */
> + /* Release instance object identified by PTR pointer. */
> void release_object_overhead (void *ptr);
>
> + /* Unregister a memory allocation descriptor registered with
> + register_descriptor (remove from reverse map), unless it is
> + unregistered through release_instance_overhead with
> + REMOVE_FROM_MAP = true. */
> + void unregister_descriptor (void *ptr);
> +
> /* Get sum value for ORIGIN type of allocation for the descriptor. */
> T get_sum (mem_alloc_origin origin);
>
> @@ -522,7 +528,7 @@ mem_alloc_description<T>::release_instan
> return usage;
> }
>
> -/* Release intance object identified by PTR pointer. */
> +/* Release instance object identified by PTR pointer. */
>
> template <class T>
> inline void
> @@ -536,6 +542,17 @@ mem_alloc_description<T>::release_object
> }
> }
>
> +/* Unregister a memory allocation descriptor registered with
> + register_descriptor (remove from reverse map), unless it is
> + unregistered through release_instance_overhead with
> + REMOVE_FROM_MAP = true. */
> +template <class T>
> +inline void
> +mem_alloc_description<T>::unregister_descriptor (void *ptr)
> +{
> + m_reverse_map->remove (ptr);
> +}
> +
> /* Default contructor. */
>
> template <class T>
> --- gcc/hash-table.h.jj 2019-03-26 08:52:52.739640547 +0100
> +++ gcc/hash-table.h 2019-03-26 09:26:27.697864773 +0100
> @@ -652,12 +652,13 @@ hash_table<Descriptor, Lazy, Allocator>:
> Allocator <value_type> ::data_free (m_entries);
> else
> ggc_free (m_entries);
> + if (m_gather_mem_stats)
> + hash_table_usage ().release_instance_overhead (this,
> + sizeof (value_type)
> + * m_size, true);
> }
> -
> - if (m_gather_mem_stats)
> - hash_table_usage ().release_instance_overhead (this,
> - sizeof (value_type)
> - * m_size, true);
> + else if (m_gather_mem_stats)
> + hash_table_usage ().unregister_descriptor (this);
> }
>
> /* This function returns an array of empty hash table elements. */
>
>
> Jakub
>
