linux-kernel - Is it safe to kmalloc a large size of memory in interrupt handler?

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Message-ID: <CABXRUiSuZc+W7884ek9YifKdx1eiJ_pmyRM42KK0ZhSK9xTkFw@mail.gmail.com>
Date:   Mon, 5 Aug 2019 19:57:54 +0800
From:   Fuqian Huang <huangfq.daxian@...il.com>
To:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Is it safe to kmalloc a large size of memory in interrupt handler?

In the implementation of kmalloc.
when the allocated size is larger than KMALLOC_MAX_CACHE_SIZE,
it will call kmalloc_large to allocate the memory.
kmalloc_large ->
kmalloc_order_trace->kmalloc_order->alloc_pages->alloc_pages_current->alloc_pages_nodemask->get_page_from_freelist->node_reclaim->__node_reclaim->shrink_node->shrink_node_memcg->get_scan_count

get_scan_count will call spin_unlock_irq which enables local interrupt.
As the local interrupt should be disabled in the interrupt handler.
It is safe to use kmalloc to allocate a large size of memory in
interrupt handler?