From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Mike Galbraith <efault@gmx.de>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-rt-users@vger.kernel.org
Subject: Re: scheduling while atomic in z3fold
Date: Mon, 30 Nov 2020 14:20:14 +0100 [thread overview]
Message-ID: <20201130132014.mlvxeyiub3fpwyw7@linutronix.de> (raw)
In-Reply-To: <90c4857c53b657147bfb71a281ece9839b0373c2.camel@gmx.de>
On 2020-11-29 12:41:14 [+0100], Mike Galbraith wrote:
> On Sun, 2020-11-29 at 12:29 +0100, Oleksandr Natalenko wrote:
> >
> > Ummm so do compressors explode under non-rt kernel in your tests as
> > well, or it is just -rt that triggers this?
>
> I only tested a non-rt kernel with z3fold, which worked just fine.
I tried this and it did not not explode yet. Mike, can you please
confirm?
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 18feaa0bc5377..0bf70f624a4bd 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -642,14 +642,17 @@ static inline void add_to_unbuddied(struct z3fold_pool *pool,
{
if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0 ||
zhdr->middle_chunks == 0) {
- struct list_head *unbuddied = get_cpu_ptr(pool->unbuddied);
-
+ struct list_head *unbuddied;
int freechunks = num_free_chunks(zhdr);
+
+ migrate_disable();
+ unbuddied = this_cpu_ptr(pool->unbuddied);
+
spin_lock(&pool->lock);
list_add(&zhdr->buddy, &unbuddied[freechunks]);
spin_unlock(&pool->lock);
zhdr->cpu = smp_processor_id();
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
}
}
@@ -887,7 +890,8 @@ static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool,
lookup:
/* First, try to find an unbuddied z3fold page. */
- unbuddied = get_cpu_ptr(pool->unbuddied);
+ migrate_disable();
+ unbuddied = this_cpu_ptr(pool->unbuddied);
for_each_unbuddied_list(i, chunks) {
struct list_head *l = &unbuddied[i];
@@ -905,7 +909,7 @@ static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool,
!z3fold_page_trylock(zhdr)) {
spin_unlock(&pool->lock);
zhdr = NULL;
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
if (can_sleep)
cond_resched();
goto lookup;
@@ -919,7 +923,7 @@ static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool,
test_bit(PAGE_CLAIMED, &page->private)) {
z3fold_page_unlock(zhdr);
zhdr = NULL;
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
if (can_sleep)
cond_resched();
goto lookup;
@@ -934,7 +938,7 @@ static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool,
kref_get(&zhdr->refcount);
break;
}
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
if (!zhdr) {
int cpu;
diff --git a/mm/zswap.c b/mm/zswap.c
index 78a20f7b00f2c..b24f761b9241c 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -394,7 +394,9 @@ struct zswap_comp {
u8 *dstmem;
};
-static DEFINE_PER_CPU(struct zswap_comp, zswap_comp);
+static DEFINE_PER_CPU(struct zswap_comp, zswap_comp) = {
+ .lock = INIT_LOCAL_LOCK(lock),
+};
static int zswap_dstmem_prepare(unsigned int cpu)
{
> -Mike
Sebastian
next prev parent reply other threads:[~2020-11-30 13:20 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-28 14:05 scheduling while atomic in z3fold Oleksandr Natalenko
2020-11-28 14:09 ` Oleksandr Natalenko
2020-11-28 14:27 ` Oleksandr Natalenko
2020-11-29 6:41 ` Mike Galbraith
[not found] ` <79ee43026efe5aaa560953ea8fe29a826ac4e855.camel@gmx.de>
2020-11-29 9:21 ` Mike Galbraith
2020-11-29 10:56 ` Mike Galbraith
2020-11-29 11:29 ` Oleksandr Natalenko
2020-11-29 11:41 ` Mike Galbraith
2020-11-30 13:20 ` Sebastian Andrzej Siewior [this message]
2020-11-30 13:53 ` Oleksandr Natalenko
2020-11-30 14:28 ` Sebastian Andrzej Siewior
2020-11-30 14:42 ` Mike Galbraith
2020-11-30 14:52 ` Sebastian Andrzej Siewior
2020-11-30 15:01 ` Mike Galbraith
2020-11-30 15:03 ` Mike Galbraith
2020-11-30 16:03 ` Sebastian Andrzej Siewior
2020-11-30 16:27 ` Mike Galbraith
2020-11-30 16:32 ` Sebastian Andrzej Siewior
2020-11-30 16:36 ` Mike Galbraith
2020-11-30 19:09 ` Mike Galbraith
2020-11-30 16:53 ` Mike Galbraith
2020-12-02 2:30 ` Mike Galbraith
[not found] ` <20201202220826.5chy56mbgvrwmg3d@linutronix.de>
2020-12-03 2:16 ` Mike Galbraith
2020-12-03 8:18 ` Mike Galbraith
2020-12-03 13:39 ` Sebastian Andrzej Siewior
2020-12-03 14:07 ` Vitaly Wool
2020-12-06 9:18 ` Mike Galbraith
2020-12-07 1:05 ` Vitaly Wool
2020-12-07 2:18 ` Mike Galbraith
2020-12-07 11:52 ` Vitaly Wool
2020-12-07 12:34 ` Mike Galbraith
2020-12-07 15:21 ` Vitaly Wool
2020-12-07 15:41 ` Sebastian Andrzej Siewior
2020-12-07 15:41 ` Mike Galbraith
2020-12-08 23:26 ` Vitaly Wool
2020-12-09 6:13 ` Mike Galbraith
2020-12-09 6:31 ` Mike Galbraith
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