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bh=gSb6lgbkEKRFaGdmBWqMU23xZBo4EVXhsGFHPgqXa7w=; b=plGLnARnD3U8Uah8oEJTxEeCxKAKAwcyFtlyiYW8fTObVVSFkehvHvC9WdlIkE3BNa iZeJVLGf/rSO70rzV6AcDrtyxMRclkac4dQChOlJT+XLR8bLo1Swgp/fiRnhEc1im6AH Pk3tgOeAihVPRBUINdaIjIjjQs8jwnncES+ayPh7osTm10B/cjHV3zGanrtGRXsSJzfE 2MP1Zm73dBdqInK86h+MOmBhbDqtQ3KpLi3KdlfEUnFQCHtjn8Y5Hgbiwz88I/P8mp6T WliHBYhYflVKvRga6ws1mk0acch7qKl2MhusZibIRKnGHcPDAEwavOn3ELTEHXgzoatY wPKw== X-Gm-Message-State: ABuFfohNv0caIJHyJHu7CdcKIV58HlRuvXpgvmT/ITbrku6xaMcQlyKh vt/N+L58VoctfvSDncTfnhIMCRNrBtLr8Tdzg0UiRg== X-Google-Smtp-Source: ACcGV61vbdBABHXl3/nbvN958bX3wlKgDNxC6FrXEKNKUpuE5TEPNIGSEQfe7x8BljakllDbHtq5xtNYRmBzI1DZJxw= X-Received: by 2002:a24:6e87:: with SMTP id w129-v6mr228244itc.49.1538080918370; Thu, 27 Sep 2018 13:41:58 -0700 (PDT) MIME-Version: 1.0 References: <1538079759.qxp8zh3nwh.astroid@alex-archsus.none> In-Reply-To: <1538079759.qxp8zh3nwh.astroid@alex-archsus.none> From: Dan Streetman Date: Thu, 27 Sep 2018 16:41:21 -0400 Message-ID: Subject: Re: [PATCH] mm: fix z3fold warnings on CONFIG_SMP=n To: alex_y_xu@yahoo.ca Cc: Linux-MM , linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 27, 2018 at 4:27 PM Alex Xu (Hello71) wrote: > > Spinlocks are always lockable on UP systems, even if they were just > locked. i think it would be much better to just use either assert_spin_locked() or just spin_is_locked(), instead of an #ifdef. > > Cc: Dan Streetman > Signed-off-by: Alex Xu (Hello71) > --- > mm/z3fold.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/mm/z3fold.c b/mm/z3fold.c > index 4b366d181..4e6ad2de4 100644 > --- a/mm/z3fold.c > +++ b/mm/z3fold.c > @@ -202,6 +202,13 @@ static inline void z3fold_page_lock(struct z3fold_header *zhdr) > spin_lock(&zhdr->page_lock); > } > > +static inline void z3fold_page_ensure_locked(struct z3fold_header *zhdr) > +{ > +#ifdef CONFIG_SMP > + WARN_ON(z3fold_page_trylock(zhdr)); > +#endif > +} > + > /* Try to lock a z3fold page */ > static inline int z3fold_page_trylock(struct z3fold_header *zhdr) > { > @@ -277,7 +284,7 @@ static void release_z3fold_page_locked(struct kref *ref) > { > struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, > refcount); > - WARN_ON(z3fold_page_trylock(zhdr)); > + z3fold_page_ensure_locked(zhdr); > __release_z3fold_page(zhdr, true); > } > > @@ -289,7 +296,7 @@ static void release_z3fold_page_locked_list(struct kref *ref) > list_del_init(&zhdr->buddy); > spin_unlock(&zhdr->pool->lock); > > - WARN_ON(z3fold_page_trylock(zhdr)); > + z3fold_page_ensure_locked(zhdr); > __release_z3fold_page(zhdr, true); > } > > @@ -403,7 +410,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked) > > page = virt_to_page(zhdr); > if (locked) > - WARN_ON(z3fold_page_trylock(zhdr)); > + z3fold_page_ensure_locked(zhdr); > else > z3fold_page_lock(zhdr); > if (WARN_ON(!test_and_clear_bit(NEEDS_COMPACTING, &page->private))) { > -- > 2.19.0 >