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63 lines
2.4 KiB
63 lines
2.4 KiB
4 years ago
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From 32bd5c04ec418a69b6e9701faa84ef0a7abb2745 Mon Sep 17 00:00:00 2001
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From: Alaa Hleihel <ahleihel@redhat.com>
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Date: Tue, 12 May 2020 10:53:35 -0400
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Subject: [PATCH 129/312] [netdrv] mlx5: work around high stack usage with gcc
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Message-id: <20200512105530.4207-10-ahleihel@redhat.com>
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Patchwork-id: 306881
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Patchwork-instance: patchwork
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O-Subject: [RHEL8.3 BZ 1789382 009/124] mlx5: work around high stack usage with gcc
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Bugzilla: 1789382
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RH-Acked-by: Tony Camuso <tcamuso@redhat.com>
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RH-Acked-by: Kamal Heib <kheib@redhat.com>
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RH-Acked-by: Jarod Wilson <jarod@redhat.com>
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Bugzilla: http://bugzilla.redhat.com/1789382
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Upstream: v5.6-rc1
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commit 42ae1a5c76691928ed217c7e40269db27f5225e9
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Author: Arnd Bergmann <arnd@arndb.de>
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Date: Sat Jan 4 22:51:44 2020 +0100
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mlx5: work around high stack usage with gcc
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In some configurations, gcc tries too hard to optimize this code:
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drivers/net/ethernet/mellanox/mlx5/core/en_stats.c: In function 'mlx5e_grp_sw_update_stats':
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drivers/net/ethernet/mellanox/mlx5/core/en_stats.c:302:1: error: the frame size of 1336 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
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As was stated in the bug report, the reason is that gcc runs into a corner
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case in the register allocator that is rather hard to fix in a good way.
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As there is an easy way to work around it, just add a comment and the
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barrier that stops gcc from trying to overoptimize the function.
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Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92657
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Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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Signed-off-by: Alaa Hleihel <ahleihel@redhat.com>
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Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
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---
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drivers/net/ethernet/mellanox/mlx5/core/en_stats.c | 3 +++
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1 file changed, 3 insertions(+)
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diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
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index 23587f55fad7..30b216d9284c 100644
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--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
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+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
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@@ -349,6 +349,9 @@ static MLX5E_DECLARE_STATS_GRP_OP_UPDATE_STATS(sw)
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s->tx_tls_drop_bypass_req += sq_stats->tls_drop_bypass_req;
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#endif
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s->tx_cqes += sq_stats->cqes;
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+
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+ /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92657 */
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+ barrier();
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}
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}
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}
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--
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2.13.6
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