| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20230719134500.GB91858@ziqianlu-dell>
Date: Wed, 19 Jul 2023 21:45:00 +0800
From: Aaron Lu <aaron.lu@...el.com>
To: Peter Zijlstra <peterz@...radead.org>
CC: Ingo Molnar <mingo@...hat.com>, Juri Lelli <juri.lelli@...hat.com>,
Vincent Guittot <vincent.guittot@...aro.org>,
Daniel Jordan <daniel.m.jordan@...cle.com>,
Dietmar Eggemann <dietmar.eggemann@....com>,
Steven Rostedt <rostedt@...dmis.org>,
Ben Segall <bsegall@...gle.com>,
"Mel Gorman" <mgorman@...e.de>,
Daniel Bristot de Oliveira <bristot@...hat.com>,
Valentin Schneider <vschneid@...hat.com>,
Tim Chen <tim.c.chen@...el.com>,
Nitin Tekchandani <nitin.tekchandani@...el.com>,
Yu Chen <yu.c.chen@...el.com>,
Waiman Long <longman@...hat.com>,
<linux-kernel@...r.kernel.org>, <yury.norov@...il.com>,
<andriy.shevchenko@...ux.intel.com>, <linux@...musvillemoes.dk>,
<rppt@...nel.org>
Subject: Re: [RFC PATCH 2/4] sched/fair: Make tg->load_avg per node
On Wed, Jul 19, 2023 at 01:53:58PM +0200, Peter Zijlstra wrote:
> On Tue, Jul 18, 2023 at 09:41:18PM +0800, Aaron Lu wrote:
> > +#if defined(CONFIG_FAIR_GROUP_SCHED) && defined(CONFIG_SMP)
> > +static inline long tg_load_avg(struct task_group *tg)
> > +{
> > + long load_avg = 0;
> > + int i;
> > +
> > + /*
> > + * The only path that can give us a root_task_group
> > + * here is from print_cfs_rq() thus unlikely.
> > + */
> > + if (unlikely(tg == &root_task_group))
> > + return 0;
> > +
> > + for_each_node(i)
> > + load_avg += atomic_long_read(&tg->node_info[i]->load_avg);
> > +
> > + return load_avg;
> > +}
> > +#endif
>
> So I was working on something else numa and noticed that for_each_node()
> (and most of the nodemask stuff) is quite moronic, afaict we should do
> something like the below.
>
> I now see Mike added the nr_node_ids thing fairly recent, but given
> distros have NODES_SHIFT=10 and actual machines typically only have <=4
> nodes, this would save a factor of 256 scanning.
Nice :-)
>
> Specifically, your for_each_node() would scan the full 1024 bit bitmap
> looking for more bits that would never be there.
Yes indeed.
I'll rebase this per-node patch on top of below diff.
Thanks for the info.
>
> ---
>
> diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
> index 8d07116caaf1..c23c0889b8cf 100644
> --- a/include/linux/nodemask.h
> +++ b/include/linux/nodemask.h
> @@ -109,7 +109,7 @@ extern nodemask_t _unused_nodemask_arg_;
> __nodemask_pr_bits(maskp)
> static inline unsigned int __nodemask_pr_numnodes(const nodemask_t *m)
> {
> - return m ? MAX_NUMNODES : 0;
> + return m ? nr_node_ids : 0;
> }
> static inline const unsigned long *__nodemask_pr_bits(const nodemask_t *m)
> {
> @@ -137,13 +137,13 @@ static inline void __node_clear(int node, volatile nodemask_t *dstp)
> clear_bit(node, dstp->bits);
> }
>
> -#define nodes_setall(dst) __nodes_setall(&(dst), MAX_NUMNODES)
> +#define nodes_setall(dst) __nodes_setall(&(dst), nr_node_ids)
> static inline void __nodes_setall(nodemask_t *dstp, unsigned int nbits)
> {
> bitmap_fill(dstp->bits, nbits);
> }
>
> -#define nodes_clear(dst) __nodes_clear(&(dst), MAX_NUMNODES)
> +#define nodes_clear(dst) __nodes_clear(&(dst), nr_node_ids)
> static inline void __nodes_clear(nodemask_t *dstp, unsigned int nbits)
> {
> bitmap_zero(dstp->bits, nbits);
> @@ -160,7 +160,7 @@ static inline bool __node_test_and_set(int node, nodemask_t *addr)
> }
>
> #define nodes_and(dst, src1, src2) \
> - __nodes_and(&(dst), &(src1), &(src2), MAX_NUMNODES)
> + __nodes_and(&(dst), &(src1), &(src2), nr_node_ids)
> static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
> const nodemask_t *src2p, unsigned int nbits)
> {
> @@ -168,7 +168,7 @@ static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
> }
>
> #define nodes_or(dst, src1, src2) \
> - __nodes_or(&(dst), &(src1), &(src2), MAX_NUMNODES)
> + __nodes_or(&(dst), &(src1), &(src2), nr_node_ids)
> static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
> const nodemask_t *src2p, unsigned int nbits)
> {
> @@ -176,7 +176,7 @@ static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
> }
>
> #define nodes_xor(dst, src1, src2) \
> - __nodes_xor(&(dst), &(src1), &(src2), MAX_NUMNODES)
> + __nodes_xor(&(dst), &(src1), &(src2), nr_node_ids)
> static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
> const nodemask_t *src2p, unsigned int nbits)
> {
> @@ -184,7 +184,7 @@ static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
> }
>
> #define nodes_andnot(dst, src1, src2) \
> - __nodes_andnot(&(dst), &(src1), &(src2), MAX_NUMNODES)
> + __nodes_andnot(&(dst), &(src1), &(src2), nr_node_ids)
> static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
> const nodemask_t *src2p, unsigned int nbits)
> {
> @@ -192,7 +192,7 @@ static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
> }
>
> #define nodes_complement(dst, src) \
> - __nodes_complement(&(dst), &(src), MAX_NUMNODES)
> + __nodes_complement(&(dst), &(src), nr_node_ids)
> static inline void __nodes_complement(nodemask_t *dstp,
> const nodemask_t *srcp, unsigned int nbits)
> {
> @@ -200,7 +200,7 @@ static inline void __nodes_complement(nodemask_t *dstp,
> }
>
> #define nodes_equal(src1, src2) \
> - __nodes_equal(&(src1), &(src2), MAX_NUMNODES)
> + __nodes_equal(&(src1), &(src2), nr_node_ids)
> static inline bool __nodes_equal(const nodemask_t *src1p,
> const nodemask_t *src2p, unsigned int nbits)
> {
> @@ -208,7 +208,7 @@ static inline bool __nodes_equal(const nodemask_t *src1p,
> }
>
> #define nodes_intersects(src1, src2) \
> - __nodes_intersects(&(src1), &(src2), MAX_NUMNODES)
> + __nodes_intersects(&(src1), &(src2), nr_node_ids)
> static inline bool __nodes_intersects(const nodemask_t *src1p,
> const nodemask_t *src2p, unsigned int nbits)
> {
> @@ -216,33 +216,33 @@ static inline bool __nodes_intersects(const nodemask_t *src1p,
> }
>
> #define nodes_subset(src1, src2) \
> - __nodes_subset(&(src1), &(src2), MAX_NUMNODES)
> + __nodes_subset(&(src1), &(src2), nr_node_ids)
> static inline bool __nodes_subset(const nodemask_t *src1p,
> const nodemask_t *src2p, unsigned int nbits)
> {
> return bitmap_subset(src1p->bits, src2p->bits, nbits);
> }
>
> -#define nodes_empty(src) __nodes_empty(&(src), MAX_NUMNODES)
> +#define nodes_empty(src) __nodes_empty(&(src), nr_node_ids)
> static inline bool __nodes_empty(const nodemask_t *srcp, unsigned int nbits)
> {
> return bitmap_empty(srcp->bits, nbits);
> }
>
> -#define nodes_full(nodemask) __nodes_full(&(nodemask), MAX_NUMNODES)
> +#define nodes_full(nodemask) __nodes_full(&(nodemask), nr_node_ids)
> static inline bool __nodes_full(const nodemask_t *srcp, unsigned int nbits)
> {
> return bitmap_full(srcp->bits, nbits);
> }
>
> -#define nodes_weight(nodemask) __nodes_weight(&(nodemask), MAX_NUMNODES)
> +#define nodes_weight(nodemask) __nodes_weight(&(nodemask), nr_node_ids)
> static inline int __nodes_weight(const nodemask_t *srcp, unsigned int nbits)
> {
> return bitmap_weight(srcp->bits, nbits);
> }
>
> #define nodes_shift_right(dst, src, n) \
> - __nodes_shift_right(&(dst), &(src), (n), MAX_NUMNODES)
> + __nodes_shift_right(&(dst), &(src), (n), nr_node_ids)
> static inline void __nodes_shift_right(nodemask_t *dstp,
> const nodemask_t *srcp, int n, int nbits)
> {
> @@ -250,7 +250,7 @@ static inline void __nodes_shift_right(nodemask_t *dstp,
> }
>
> #define nodes_shift_left(dst, src, n) \
> - __nodes_shift_left(&(dst), &(src), (n), MAX_NUMNODES)
> + __nodes_shift_left(&(dst), &(src), (n), nr_node_ids)
> static inline void __nodes_shift_left(nodemask_t *dstp,
> const nodemask_t *srcp, int n, int nbits)
> {
> @@ -385,7 +385,7 @@ static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
> #if MAX_NUMNODES > 1
> #define for_each_node_mask(node, mask) \
> for ((node) = first_node(mask); \
> - (node) < MAX_NUMNODES; \
> + (node) < nr_node_ids; \
> (node) = next_node((node), (mask)))
> #else /* MAX_NUMNODES == 1 */
> #define for_each_node_mask(node, mask) \
Powered by blists - more mailing lists