Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 22 May 2023 23:12:08 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc:     linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        LKML <linux-kernel@vger.kernel.org>, Baoquan He <bhe@redhat.com>,
        Lorenzo Stoakes <lstoakes@gmail.com>,
        Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>,
        "Liam R . Howlett" <Liam.Howlett@oracle.com>,
        Dave Chinner <david@fromorbit.com>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Subject: Re: [PATCH 5/9] mm: vmalloc: Insert busy-VA per-cpu zone
Message-ID: <ZGxZOGpaq9ybRLZ7@infradead.org>
References: <20230522110849.2921-1-urezki@gmail.com>
 <20230522110849.2921-6-urezki@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230522110849.2921-6-urezki@gmail.com>
Precedence: bulk

>  /* Look up the first VA which satisfies addr < va_end, NULL if none. */
> -static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
> +static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr, struct rb_root *root)

Please avoid the overly long line.

> +	struct cpu_vmap_zone *z = addr_to_cvz(va->va_start);
> +
>  	/*
>  	 * Remove from the busy tree/list.
>  	 */
> -	spin_lock(&vmap_area_lock);
> -	unlink_va(va, &vmap_area_root);
> -	spin_unlock(&vmap_area_lock);
> +	fbl_lock(z, BUSY);
> +	unlink_va(va, &fbl_root(z, BUSY));
> +	fbl_unlock(z, BUSY);

I find the BUSY magic here very confusing, and would prefer to
just spell the actual lock reference out.