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charset=us-ascii Content-Disposition: inline X-Rspamd-Queue-Id: 2E6DF40069 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: krd19cyffn5qobpxy8oyy1kojeaahqrj X-HE-Tag: 1684937439-942594 X-HE-Meta: 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 fxp3eAFB RhmBfs51pmLUJadbn9gslRwu0ToTlRnw+YzYucE5RSyRDLudC2gKcT5vR4oovEHGuiPCtzG3VdrmAIFDaRdAw6K37/EKIbFflBejrz9arsF9jBafaAtmqi4ItOZRJYxs/ZprDoY1QpF5mnOtbFVTPc2807wzkCnBU4daP6b3VKZ9twmWTi/F6dhiRfLhhRnSZjUx4ssMB8uJ8dYw= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 05/24/23 at 11:52am, Thomas Gleixner wrote: > On Wed, May 24 2023 at 17:32, Baoquan He wrote: > > On 05/23/23 at 04:02pm, Thomas Gleixner wrote: > >> @@ -2236,9 +2236,10 @@ static void _vm_unmap_aliases(unsigned l > >> for_each_possible_cpu(cpu) { > >> struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); > >> struct vmap_block *vb; > >> + unsigned long idx; > >> > >> rcu_read_lock(); > > > > Do we need to remove this rcu_read_xx() pair since it marks the RCU > > read-side critical section on vbq-free list? > > And what protects the xarray lookup? We have put rcu_read_lock() pair around the xas_find(). And it will find into xarray for each iteration item. We won't lose the connection to the next element like list adding or deleting? not very sure, I could be wrong. xa_for_each() -->xa_for_each_start() -->xa_for_each_range() -->xa_find() void *xa_find(struct xarray *xa, unsigned long *indexp, unsigned long max, xa_mark_t filter) { ...... rcu_read_lock(); do { if ((__force unsigned int)filter < XA_MAX_MARKS) entry = xas_find_marked(&xas, max, filter); else entry = xas_find(&xas, max); } while (xas_retry(&xas, entry)); rcu_read_unlock(); if (entry) *indexp = xas.xa_index; return entry; } > > >> - list_for_each_entry_rcu(vb, &vbq->free, free_list) { > >> + xa_for_each(&vbq->vmap_blocks, idx, vb) { > >> spin_lock(&vb->lock); > >> if (vb->dirty && vb->dirty != VMAP_BBMAP_BITS) { > >> unsigned long va_start = vb->va->va_start; > >> >