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[86.164.169.89]) by smtp.gmail.com with ESMTPSA id g2-20020a5d4882000000b00286ad197346sm26207750wrq.70.2023.01.16.04.22.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Jan 2023 04:22:09 -0800 (PST) Date: Mon, 16 Jan 2023 12:22:08 +0000 From: Lorenzo Stoakes To: Baoquan He Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, urezki@gmail.com, stephen.s.brennan@oracle.com, willy@infradead.org, akpm@linux-foundation.org, hch@infradead.org Subject: Re: [PATCH v3 1/7] mm/vmalloc.c: add used_map into vmap_block to track space of vmap_block Message-ID: References: <20230113031921.64716-1-bhe@redhat.com> <20230113031921.64716-2-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230113031921.64716-2-bhe@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 13, 2023 at 11:19:15AM +0800, Baoquan He wrote: > In one vmap_block area, there could be three types of regions: region > being used which is allocated through vb_alloc(), dirty region which > is freed via vb_free() and free region. Among them, only used region > has available data. While there's no way to track those used regions > currently. > > Here, add bitmap field used_map into vmap_block, and set/clear it during > allocation or freeing regions of vmap_block area. > > This is a preparatoin for later use. > > Signed-off-by: Baoquan He > --- > mm/vmalloc.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 428e0bee5c9c..d6ff058ef4d0 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1922,6 +1922,7 @@ struct vmap_block { > spinlock_t lock; > struct vmap_area *va; > unsigned long free, dirty; > + DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS); > unsigned long dirty_min, dirty_max; /*< dirty range */ > struct list_head free_list; > struct rcu_head rcu_head; > @@ -1998,10 +1999,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) > vb->va = va; > /* At least something should be left free */ > BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); > + bitmap_zero(vb->used_map, VMAP_BBMAP_BITS); > vb->free = VMAP_BBMAP_BITS - (1UL << order); > vb->dirty = 0; > vb->dirty_min = VMAP_BBMAP_BITS; > vb->dirty_max = 0; > + bitmap_set(vb->used_map, 0, (1UL << order)); > INIT_LIST_HEAD(&vb->free_list); > > vb_idx = addr_to_vb_idx(va->va_start); > @@ -2111,6 +2114,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) > pages_off = VMAP_BBMAP_BITS - vb->free; > vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); > vb->free -= 1UL << order; > + bitmap_set(vb->used_map, pages_off, (1UL << order)); > if (vb->free == 0) { > spin_lock(&vbq->lock); > list_del_rcu(&vb->free_list); > @@ -2144,6 +2148,9 @@ static void vb_free(unsigned long addr, unsigned long size) > order = get_order(size); > offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; > vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr)); > + spin_lock(&vb->lock); > + bitmap_clear(vb->used_map, offset, (1UL << order)); > + spin_unlock(&vb->lock); > > vunmap_range_noflush(addr, addr + size); > > -- > 2.34.1 > Reviewed-by: Lorenzo Stoakes