From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>,
xen-devel <xen-devel@lists.xenproject.org>,
Keir Fraser <keir@xen.org>,
Ian Jackson <Ian.Jackson@eu.citrix.com>, Tim Deegan <tim@xen.org>
Subject: Re: [PATCH] switch rangeset's lock to rwlock
Date: Fri, 19 Sep 2014 12:32:02 -0400 [thread overview]
Message-ID: <20140919163202.GA9327@laptop.dumpdata.com> (raw)
In-Reply-To: <5413094B020000780003480E@mail.emea.novell.com>
On Fri, Sep 12, 2014 at 01:55:07PM +0100, Jan Beulich wrote:
> As a general library routine, it should behave as efficiently as
> possible, even if at present no significant contention is known here.
>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
I am comfortable with this going to Xen 4.5.
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> With the widened use of rangesets I'd like to re-suggest this change
> which I had posted already a couple of years back.
>
> --- a/xen/common/rangeset.c
> +++ b/xen/common/rangeset.c
> @@ -28,7 +28,7 @@ struct rangeset {
>
> /* Number of ranges that can be allocated */
> long nr_ranges;
> - spinlock_t lock;
> + rwlock_t lock;
>
> /* Pretty-printing name. */
> char name[32];
> @@ -120,7 +120,7 @@ int rangeset_add_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + write_lock(&r->lock);
>
> x = find_range(r, s);
> y = find_range(r, e);
> @@ -176,7 +176,7 @@ int rangeset_add_range(
> }
>
> out:
> - spin_unlock(&r->lock);
> + write_unlock(&r->lock);
> return rc;
> }
>
> @@ -188,7 +188,7 @@ int rangeset_remove_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + write_lock(&r->lock);
>
> x = find_range(r, s);
> y = find_range(r, e);
> @@ -244,7 +244,7 @@ int rangeset_remove_range(
> }
>
> out:
> - spin_unlock(&r->lock);
> + write_unlock(&r->lock);
> return rc;
> }
>
> @@ -256,10 +256,10 @@ int rangeset_contains_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
> x = find_range(r, s);
> contains = (x && (x->e >= e));
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
>
> return contains;
> }
> @@ -272,10 +272,10 @@ int rangeset_overlaps_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
> x = find_range(r, e);
> overlaps = (x && (s <= x->e));
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
>
> return overlaps;
> }
> @@ -287,13 +287,13 @@ int rangeset_report_ranges(
> struct range *x;
> int rc = 0;
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
>
> for ( x = find_range(r, s); x && (x->s <= e) && !rc; x = next_range(r, x) )
> if ( x->e >= s )
> rc = cb(max(x->s, s), min(x->e, e), ctxt);
>
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
>
> return rc;
> }
> @@ -331,7 +331,7 @@ struct rangeset *rangeset_new(
> if ( r == NULL )
> return NULL;
>
> - spin_lock_init(&r->lock);
> + rwlock_init(&r->lock);
> INIT_LIST_HEAD(&r->range_list);
> r->nr_ranges = -1;
>
> @@ -414,21 +414,21 @@ void rangeset_swap(struct rangeset *a, s
>
> if ( a < b )
> {
> - spin_lock(&a->lock);
> - spin_lock(&b->lock);
> + write_lock(&a->lock);
> + write_lock(&b->lock);
> }
> else
> {
> - spin_lock(&b->lock);
> - spin_lock(&a->lock);
> + write_lock(&b->lock);
> + write_lock(&a->lock);
> }
>
> list_splice_init(&a->range_list, &tmp);
> list_splice_init(&b->range_list, &a->range_list);
> list_splice(&tmp, &b->range_list);
>
> - spin_unlock(&a->lock);
> - spin_unlock(&b->lock);
> + write_unlock(&a->lock);
> + write_unlock(&b->lock);
> }
>
> /*****************************
> @@ -446,7 +446,7 @@ void rangeset_printk(
> int nr_printed = 0;
> struct range *x;
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
>
> printk("%-10s {", r->name);
>
> @@ -465,7 +465,7 @@ void rangeset_printk(
>
> printk(" }");
>
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
> }
>
> void rangeset_domain_printk(
>
>
>
> switch rangeset's lock to rwlock
>
> As a general library routine, it should behave as efficiently as
> possible, even if at present no significant contention is known here.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> With the widened use of rangesets I'd like to re-suggest this change
> which I had posted already a couple of years back.
>
> --- a/xen/common/rangeset.c
> +++ b/xen/common/rangeset.c
> @@ -28,7 +28,7 @@ struct rangeset {
>
> /* Number of ranges that can be allocated */
> long nr_ranges;
> - spinlock_t lock;
> + rwlock_t lock;
>
> /* Pretty-printing name. */
> char name[32];
> @@ -120,7 +120,7 @@ int rangeset_add_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + write_lock(&r->lock);
>
> x = find_range(r, s);
> y = find_range(r, e);
> @@ -176,7 +176,7 @@ int rangeset_add_range(
> }
>
> out:
> - spin_unlock(&r->lock);
> + write_unlock(&r->lock);
> return rc;
> }
>
> @@ -188,7 +188,7 @@ int rangeset_remove_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + write_lock(&r->lock);
>
> x = find_range(r, s);
> y = find_range(r, e);
> @@ -244,7 +244,7 @@ int rangeset_remove_range(
> }
>
> out:
> - spin_unlock(&r->lock);
> + write_unlock(&r->lock);
> return rc;
> }
>
> @@ -256,10 +256,10 @@ int rangeset_contains_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
> x = find_range(r, s);
> contains = (x && (x->e >= e));
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
>
> return contains;
> }
> @@ -272,10 +272,10 @@ int rangeset_overlaps_range(
>
> ASSERT(s <= e);
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
> x = find_range(r, e);
> overlaps = (x && (s <= x->e));
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
>
> return overlaps;
> }
> @@ -287,13 +287,13 @@ int rangeset_report_ranges(
> struct range *x;
> int rc = 0;
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
>
> for ( x = find_range(r, s); x && (x->s <= e) && !rc; x = next_range(r, x) )
> if ( x->e >= s )
> rc = cb(max(x->s, s), min(x->e, e), ctxt);
>
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
>
> return rc;
> }
> @@ -331,7 +331,7 @@ struct rangeset *rangeset_new(
> if ( r == NULL )
> return NULL;
>
> - spin_lock_init(&r->lock);
> + rwlock_init(&r->lock);
> INIT_LIST_HEAD(&r->range_list);
> r->nr_ranges = -1;
>
> @@ -414,21 +414,21 @@ void rangeset_swap(struct rangeset *a, s
>
> if ( a < b )
> {
> - spin_lock(&a->lock);
> - spin_lock(&b->lock);
> + write_lock(&a->lock);
> + write_lock(&b->lock);
> }
> else
> {
> - spin_lock(&b->lock);
> - spin_lock(&a->lock);
> + write_lock(&b->lock);
> + write_lock(&a->lock);
> }
>
> list_splice_init(&a->range_list, &tmp);
> list_splice_init(&b->range_list, &a->range_list);
> list_splice(&tmp, &b->range_list);
>
> - spin_unlock(&a->lock);
> - spin_unlock(&b->lock);
> + write_unlock(&a->lock);
> + write_unlock(&b->lock);
> }
>
> /*****************************
> @@ -446,7 +446,7 @@ void rangeset_printk(
> int nr_printed = 0;
> struct range *x;
>
> - spin_lock(&r->lock);
> + read_lock(&r->lock);
>
> printk("%-10s {", r->name);
>
> @@ -465,7 +465,7 @@ void rangeset_printk(
>
> printk(" }");
>
> - spin_unlock(&r->lock);
> + read_unlock(&r->lock);
> }
>
> void rangeset_domain_printk(
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2014-09-19 16:32 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-12 12:55 [PATCH] switch rangeset's lock to rwlock Jan Beulich
2014-09-18 10:43 ` Tim Deegan
2014-09-18 12:15 ` Jan Beulich
2014-09-18 13:02 ` Tim Deegan
2014-09-18 13:32 ` Jan Beulich
2014-09-18 14:52 ` Paul Durrant
2014-09-19 16:33 ` Konrad Rzeszutek Wilk
2014-09-22 9:42 ` Ian Campbell
2014-09-22 10:34 ` Jan Beulich
2014-09-19 16:32 ` Konrad Rzeszutek Wilk [this message]
2014-09-30 8:50 ` Jan Beulich
2014-09-30 12:01 ` Tim Deegan
2014-09-30 20:53 ` Keir Fraser
2014-10-01 8:57 ` Jan Beulich
2014-10-01 9:31 ` Keir Fraser
-- strict thread matches above, loose matches on Subject: below --
2011-03-25 16:49 Jan Beulich
2011-03-25 17:08 ` Keir Fraser
2011-03-25 17:52 ` Dan Magenheimer
2011-03-25 20:52 ` Keir Fraser
2011-03-30 22:44 ` Jeremy Fitzhardinge
2011-03-28 8:23 ` Jan Beulich
2011-03-28 8:54 ` Keir Fraser
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