From: Linus Walleij <linus.walleij@linaro.org>
To: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Subject: [PATCH v2 1/5] fork: Clean-up ifdef logic around stack allocation
Date: Wed, 07 May 2025 14:46:27 +0200 [thread overview]
Message-ID: <20250507-fork-fixes-v2-1-82ab1e42cde3@linaro.org> (raw)
In-Reply-To: <20250507-fork-fixes-v2-0-82ab1e42cde3@linaro.org>
From: Pasha Tatashin <pasha.tatashin@soleen.com>
There is unneeded OR in the ifdef functions that are used to allocate
and free kernel stacks based on direct map or vmap.
Therefore, clean up by Changing the order so OR is no longer needed.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/20240311164638.2015063-3-pasha.tatashin@soleen.com
[linus.walleij@linaro.org: Rebased]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
kernel/fork.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index c4b26cd8998b8e7b2b516e0bb0b1d4676ff644dc..7b9e1ad141baaeb158b1807ea9fc3ef246f5f3a7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -185,13 +185,7 @@ static inline void free_task_struct(struct task_struct *tsk)
kmem_cache_free(task_struct_cachep, tsk);
}
-/*
- * Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
- * kmemcache based allocator.
- */
-# if THREAD_SIZE >= PAGE_SIZE || defined(CONFIG_VMAP_STACK)
-
-# ifdef CONFIG_VMAP_STACK
+#ifdef CONFIG_VMAP_STACK
/*
* vmalloc() is a bit slow, and calling vfree() enough times will force a TLB
* flush. Try to minimize the number of calls by caching stacks.
@@ -342,7 +336,13 @@ static void free_thread_stack(struct task_struct *tsk)
tsk->stack_vm_area = NULL;
}
-# else /* !CONFIG_VMAP_STACK */
+#else /* !CONFIG_VMAP_STACK */
+
+/*
+ * Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
+ * kmemcache based allocator.
+ */
+#if THREAD_SIZE >= PAGE_SIZE
static void thread_stack_free_rcu(struct rcu_head *rh)
{
@@ -374,8 +374,7 @@ static void free_thread_stack(struct task_struct *tsk)
tsk->stack = NULL;
}
-# endif /* CONFIG_VMAP_STACK */
-# else /* !(THREAD_SIZE >= PAGE_SIZE || defined(CONFIG_VMAP_STACK)) */
+#else /* !(THREAD_SIZE >= PAGE_SIZE) */
static struct kmem_cache *thread_stack_cache;
@@ -414,7 +413,8 @@ void thread_stack_cache_init(void)
BUG_ON(thread_stack_cache == NULL);
}
-# endif /* THREAD_SIZE >= PAGE_SIZE || defined(CONFIG_VMAP_STACK) */
+#endif /* THREAD_SIZE >= PAGE_SIZE */
+#endif /* CONFIG_VMAP_STACK */
/* SLAB cache for signal_struct structures (tsk->signal) */
static struct kmem_cache *signal_cachep;
--
2.49.0
next prev parent reply other threads:[~2025-05-07 12:46 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-07 12:46 [PATCH v2 0/5] fork: Page operation cleanups in the fork code Linus Walleij
2025-05-07 12:46 ` Linus Walleij [this message]
2025-05-13 6:29 ` [PATCH v2 1/5] fork: Clean-up ifdef logic around stack allocation Mike Rapoport
2025-05-07 12:46 ` [PATCH v2 2/5] fork: Clean-up naming of vm_stack/vm_struct variables in vmap stacks code Linus Walleij
2025-05-13 6:33 ` Mike Rapoport
2025-05-07 12:46 ` [PATCH v2 3/5] fork: Remove assumption that vm_area->nr_pages equals to THREAD_SIZE Linus Walleij
2025-05-07 16:56 ` Mateusz Guzik
2025-05-09 5:44 ` Linus Walleij
2025-05-07 12:46 ` [PATCH v2 4/5] fork: check charging success before zeroing stack Linus Walleij
2025-05-13 7:38 ` Mike Rapoport
2025-05-07 12:46 ` [PATCH v2 5/5] fork: zero vmap stack using clear_page() instead of memset() Linus Walleij
2025-05-07 16:51 ` Mateusz Guzik
2025-05-09 5:49 ` Linus Walleij
2025-05-07 17:03 ` [PATCH v2 0/5] fork: Page operation cleanups in the fork code Mateusz Guzik
2025-05-09 6:57 ` Linus Walleij
2025-05-09 11:16 ` Mateusz Guzik
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