From: Thomas Schwinge <thomas@codesourcery.com>
To: Julian Brown <julian@codesourcery.com>
Cc: <gcc-patches@gcc.gnu.org>, Jakub Jelinek <jakub@redhat.com>,
Tobias Burnus <tobias@codesourcery.com>,
<Catherine_Moore@mentor.com>
Subject: Re: [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts
Date: Thu, 16 Jul 2020 11:35:23 +0200 [thread overview]
Message-ID: <yxfpwo33x0o4.fsf@hertz.schwinge.homeip.net> (raw)
In-Reply-To: <87366i18uv.fsf@euler.schwinge.homeip.net>
Hi Julian!
Ping.
On 2020-06-26T11:20:40+0200, I wrote:
> On 2019-12-17T22:03:47-0800, Julian Brown <julian@codesourcery.com> wrote:
>> This part contains the libgomp runtime support for the GOMP_MAP_ATTACH and
>> GOMP_MAP_DETACH mapping kinds (etc.), as introduced by the front-end
>> patches following in this series.
>
>> --- a/libgomp/target.c
>> +++ b/libgomp/target.c
>
>> @@ -1534,6 +1571,18 @@ gomp_unmap_vars_internal (struct target_mem_desc *tgt, bool do_copyfrom,
>
> This is the code path at the end of a structured OpenACC 'data'
> construct.
>
>> + /* We must perform detachments before any copies back to the host. */
>> + for (i = 0; i < tgt->list_count; i++)
>> + {
>> + splay_tree_key k = tgt->list[i].key;
>> +
>> + if (k != NULL && tgt->list[i].do_detach)
>> + gomp_detach_pointer (devicep, aq, k, tgt->list[i].key->host_start
>> + + tgt->list[i].offset,
>> + k->refcount == 1, NULL);
>> + }
>
> Can you please explain (as a source code comment) the logic for here
> using 'k->refcount == 1' for the 'bool finalize' parameter of
> 'gomp_detach_pointer'; this somehow feels "strange"?
>
> Nonwithstanding the question whether that's a valid thing to do or not,
> but doesn't the current code hide the "attach count underflow" error if
> you reach the above code with 'attach_count == 0' (user already
> explicitly 'detach'ed), but then given 'k->refcount == 1' (thus
> 'finalize' semantics), 'gomp_detach_pointer' will then re-initialize
> 'attach_count = 1', and then do another 'gomp_copy_host2dev', etc.
> instead of emitting an error.
>
> (I have not attempted to produce a libgomp test case.)
>
> Shouldn't this just always be 'finalize = false' given that there is no
> 'finalize' semantics for 'detach' on a structured OpenACC 'data'
> constructs -- at least that's what I remember right now?
Grüße
Thomas
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next prev parent reply other threads:[~2020-07-16 9:35 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-10 17:11 [PATCH 0/3] OpenACC 2.6 manual deep copy support (attach/detach) Julian Brown
2018-11-10 17:11 ` [PATCH 1/3] Host-to-device transfer coalescing & magic offset value self-documentation Julian Brown
2018-12-21 10:56 ` libgomp/target.c magic constants self-documentation Thomas Schwinge
2019-05-29 14:48 ` Thomas Schwinge
2018-11-10 17:11 ` [PATCH 2/3] Factor out duplicate code in gimplify_scan_omp_clauses Julian Brown
2018-12-18 14:16 ` Julian Brown
2018-12-18 14:50 ` Jakub Jelinek
2018-11-10 17:12 ` [PATCH 3/3] OpenACC 2.6 manual deep copy support (attach/detach) Julian Brown
2018-11-11 17:04 ` Bernhard Reutner-Fischer
2018-11-30 11:41 ` [PATCH] " Julian Brown
2018-12-03 17:03 ` Julian Brown
2018-12-07 13:50 ` Jakub Jelinek
2018-12-10 19:42 ` Julian Brown
2018-12-13 10:57 ` Jakub Jelinek
2018-12-14 19:00 ` Julian Brown
2018-12-18 12:25 ` Jakub Jelinek
2018-12-22 13:37 ` Thomas Schwinge
2019-10-18 17:20 ` Thomas Schwinge
2019-11-06 18:44 ` Julian Brown
2019-11-22 23:54 ` Julian Brown
2019-11-25 10:53 ` Tobias Burnus
2019-11-26 2:54 ` Julian Brown
2019-12-17 12:16 ` Thomas Schwinge
2019-12-17 17:28 ` [WIP] OpenACC 'acc_attach*', 'acc_detach*' runtime library routines (was: [PATCH] OpenACC 2.6 manual deep copy support (attach/detach)) Thomas Schwinge
2019-12-18 6:03 ` [PATCH 00/13] OpenACC 2.6 manual deep copy support Julian Brown
2019-12-18 6:03 ` [PATCH 01/13] Use aux struct in libgomp for infrequently-used/API-specific data Julian Brown
2019-12-18 6:03 ` [PATCH 03/13] OpenACC reference count consistency checking Julian Brown
2019-12-18 6:03 ` [PATCH 02/13] OpenACC reference count overhaul Julian Brown
2020-05-19 15:42 ` Thomas Schwinge
2020-06-04 18:13 ` [OpenACC] Use 'tgt' returned from 'gomp_map_vars' (was: [PATCH 02/13] OpenACC reference count overhaul) Thomas Schwinge
2020-05-19 15:49 ` [PATCH 02/13] OpenACC reference count overhaul Thomas Schwinge
2020-05-19 15:58 ` Thomas Schwinge
2020-06-25 11:03 ` Thomas Schwinge
2020-07-03 15:29 ` Thomas Schwinge
2019-12-18 6:04 ` [PATCH 06/13] OpenACC 2.6 deep copy: attach/detach API routines Julian Brown
2019-12-18 6:04 ` [PATCH 09/13] OpenACC 2.6 deep copy: C and C++ front-end parts Julian Brown
2019-12-24 5:05 ` Thomas Schwinge
2019-12-26 19:04 ` Jason Merrill
2021-06-10 11:03 ` Thomas Schwinge
2019-12-18 6:04 ` [PATCH 04/13] Use gomp_map_val for OpenACC host-to-device address translation Julian Brown
2019-12-18 6:04 ` [PATCH 05/13] Factor out duplicate code in gimplify_scan_omp_clauses Julian Brown
2019-12-18 6:04 ` [PATCH 08/13] OpenACC 2.6 deep copy: middle-end parts Julian Brown
2019-12-21 21:51 ` Thomas Schwinge
2019-12-18 6:05 ` [PATCH 12/13] OpenACC 2.6 deep copy: Fortran execution tests Julian Brown
2019-12-18 6:05 ` [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts Julian Brown
2019-12-21 23:37 ` Thomas Schwinge
2020-01-03 12:26 ` Julian Brown
2020-05-20 9:37 ` Thomas Schwinge
2020-06-05 16:23 ` [OpenACC 'exit data'] Simplify 'GOMP_MAP_STRUCT' handling (was: [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts) Thomas Schwinge
2020-06-05 16:36 ` [OpenACC 'exit data'] Strip 'GOMP_MAP_STRUCT' mappings " Thomas Schwinge
2020-05-20 14:52 ` [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts Thomas Schwinge
2020-05-20 19:11 ` Julian Brown
2020-06-04 18:35 ` [OpenACC] Repair/restore 'is_tgt_unmapped' checking (was: [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts) Thomas Schwinge
2020-06-04 18:53 ` [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts Thomas Schwinge
2020-06-05 10:39 ` Thomas Schwinge
2020-06-05 20:28 ` Julian Brown
2020-06-05 11:17 ` Thomas Schwinge
2020-06-05 20:31 ` Julian Brown
2020-06-09 10:41 ` OpenACC 'attach'/'detach' has no business affecting user-visible reference counting (was: [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts) Thomas Schwinge
2020-06-09 12:23 ` Julian Brown
2020-06-18 18:21 ` Julian Brown
2020-07-16 8:35 ` OpenACC 'attach'/'detach' has no business affecting user-visible reference counting Thomas Schwinge
2020-06-26 9:20 ` [PATCH 07/13] OpenACC 2.6 deep copy: libgomp parts Thomas Schwinge
2020-07-16 9:35 ` Thomas Schwinge [this message]
2020-07-16 21:21 ` Julian Brown
2020-07-17 9:12 ` Thomas Schwinge
2020-06-30 15:58 ` Thomas Schwinge
2019-12-18 6:05 ` [PATCH 11/13] OpenACC 2.6 deep copy: C and C++ execution tests Julian Brown
2020-06-04 18:43 ` Fix 'sizeof' usage in 'libgomp.oacc-c-c++-common/deep-copy-{7, 8}.c' (was: [PATCH 11/13] OpenACC 2.6 deep copy: C and C++ execution tests) Thomas Schwinge
2023-10-31 14:00 ` Add OpenACC 'acc_map_data' variant to 'libgomp.oacc-c-c++-common/deep-copy-8.c' " Thomas Schwinge
2019-12-18 6:05 ` [PATCH 13/13] Fortran polymorphic class-type support for OpenACC Julian Brown
2019-12-18 7:20 ` [PATCH 10/13] OpenACC 2.6 deep copy: Fortran front-end parts Julian Brown
2019-12-18 23:30 ` Tobias Burnus
2019-12-20 12:25 ` [committed] Improve is-coindexed check for OpenACC/OpenMP (was: [PATCH 10/13] OpenACC 2.6 deep copy: Fortran front-end parts) Tobias Burnus
2019-12-20 13:25 ` [PATCH 10/13] OpenACC 2.6 deep copy: Fortran front-end parts Tobias Burnus
2019-12-20 10:08 ` [patch,committed] Fix testsuite-fallout of OpenACC deep-copy patch (was: [PATCH 10/13] OpenACC 2.6 deep copy: Fortran front-end parts) Tobias Burnus
2019-12-18 18:24 ` [PATCH 00/13] OpenACC 2.6 manual deep copy support Thomas Schwinge
2019-12-20 1:21 ` Julian Brown
2019-12-20 14:36 ` OpenACC regression and development pace Thomas Koenig
2020-06-04 18:07 ` [OpenACC] XFAIL behavior of over-eager 'finalize' clause (was: [PATCH 00/13] OpenACC 2.6 manual deep copy support) Thomas Schwinge
2019-12-17 16:53 ` In 'libgomp/target.c', 'struct splay_tree_key_s', use 'struct splay_tree_aux' for infrequently-used or API-specific data (was: [PATCH] OpenACC 2.6 manual deep copy support (attach/detach)) Thomas Schwinge
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