From: Nicholas Piggin <npiggin@gmail.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [RFC REBASED 3/5] powerpc/mm/slice: implement slice_check_range_fits
Date: Tue, 27 Feb 2018 19:04:40 +1000 [thread overview]
Message-ID: <20180227190440.45ce8641@roar.ozlabs.ibm.com> (raw)
In-Reply-To: <87k1uy7vbr.fsf@linux.vnet.ibm.com>
On Tue, 27 Feb 2018 12:50:08 +0530
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> wrote:
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
> + if ((start + len) > SLICE_LOW_TOP) {
> > + unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
> > + unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
> > + unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
> > + unsigned long i;
> >
> > - slice_bitmap_and(result, mask->high_slices, available->high_slices,
> > - slice_count);
> > + for (i = start_index; i < start_index + count; i++) {
> > + if (!test_bit(i, available->high_slices))
> > + return false;
> > + }
> > + }
>
> why not bitmap_equal here instead of test_bit in loop?
Because we only have the available bitmap now. If we see large ranges
here we could use some bitmap operation like find_next_zero_bit perhaps.
Thanks,
Nick
next prev parent reply other threads:[~2018-02-27 9:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-12 18:12 [RFC REBASED 1/5] powerpc/mm/slice: pass pointers to struct slice_mask where possible Christophe Leroy
2018-02-12 18:12 ` [RFC REBASED 2/5] powerpc/mm/slice: implement a slice mask cache Christophe Leroy
2018-02-12 18:12 ` [RFC REBASED 3/5] powerpc/mm/slice: implement slice_check_range_fits Christophe Leroy
2018-02-27 7:20 ` Aneesh Kumar K.V
2018-02-27 9:04 ` Nicholas Piggin [this message]
2018-02-12 18:12 ` [RFC REBASED 4/5] powerpc/mm/slice: Use const pointers to cached slice masks where possible Christophe Leroy
2018-02-27 7:29 ` Aneesh Kumar K.V
2018-02-27 9:08 ` Nicholas Piggin
2018-02-12 18:12 ` [RFC REBASED 5/5] powerpc/mm/slice: use the dynamic high slice size to limit bitmap operations Christophe Leroy
2018-02-27 9:01 ` Aneesh Kumar K.V
2018-02-27 9:11 ` Nicholas Piggin
2018-02-27 12:41 ` Aneesh Kumar K.V
2018-02-28 6:53 ` Nicholas Piggin
2018-02-28 6:59 ` Aneesh Kumar K.V
2018-03-01 7:09 ` Christophe LEROY
2018-03-01 9:22 ` Nicholas Piggin
2018-02-28 7:07 ` Aneesh Kumar K.V
[not found] ` <87muzu7w58.fsf@linux.vnet.ibm.com>
2018-02-27 7:04 ` [RFC REBASED 1/5] powerpc/mm/slice: pass pointers to struct slice_mask where possible Christophe LEROY
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