Skip to main content

Browse the archive

Revision 72f961320d5d15bfcb26dbe3edaa3f7d25fd2c8a authored by Paolo Abeni on 10 June 2021, 22:59:40 UTC, committed by David S. Miller on 10 June 2021, 23:47:44 UTC 
mptcp: try harder to borrow memory from subflow under pressure
 
If the host is under sever memory pressure, and RX forward
memory allocation for the msk fails, we try to borrow the
required memory from the ingress subflow.

The current attempt is a bit flaky: if skb->truesize is less
than SK_MEM_QUANTUM, the ssk will not release any memory, and
the next schedule will fail again.

Instead, directly move the required amount of pages from the
ssk to the msk, if available

Fixes: 9c3f94e1681b ("mptcp: add missing memory scheduling in the rx path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 22488e4
Raw File
failslab.c 
// SPDX-License-Identifier: GPL-2.0
#include <linux/fault-inject.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include "slab.h"

static struct {
	struct fault_attr attr;
	bool ignore_gfp_reclaim;
	bool cache_filter;
} failslab = {
	.attr = FAULT_ATTR_INITIALIZER,
	.ignore_gfp_reclaim = true,
	.cache_filter = false,
};

bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags)
{
	/* No fault-injection for bootstrap cache */
	if (unlikely(s == kmem_cache))
		return false;

	if (gfpflags & __GFP_NOFAIL)
		return false;

	if (failslab.ignore_gfp_reclaim &&
			(gfpflags & __GFP_DIRECT_RECLAIM))
		return false;

	if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
		return false;

	return should_fail(&failslab.attr, s->object_size);
}

static int __init setup_failslab(char *str)
{
	return setup_fault_attr(&failslab.attr, str);
}
__setup("failslab=", setup_failslab);

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
static int __init failslab_debugfs_init(void)
{
	struct dentry *dir;
	umode_t mode = S_IFREG | 0600;

	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
	if (IS_ERR(dir))
		return PTR_ERR(dir);

	debugfs_create_bool("ignore-gfp-wait", mode, dir,
			    &failslab.ignore_gfp_reclaim);
	debugfs_create_bool("cache-filter", mode, dir,
			    &failslab.cache_filter);

	return 0;
}

late_initcall(failslab_debugfs_init);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
back to top