linux/drivers/infiniband/hw/hfi1/mmu_rb.h
Sebastian Sanchez 7be85676f1 IB/hfi1: Don't remove RB entry when not needed.
An RB tree is used for the SDMA pinning cache. Cache
entries are extracted and reinserted from the tree
in case the address range for it changes. However,
if the address range for the entry doesn't change,
deleting the entry from the RB tree is not necessary.

This affects performance since the tree needs to be
rebalanced for each insertion, and this happens in
the hot path. Optimize RB search by not removing
entries when it's not needed.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-06-27 16:56:33 -04:00

89 lines
3.5 KiB
C

/*
* Copyright(c) 2016 Intel Corporation.
*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* BSD LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
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* - Redistributions of source code must retain the above copyright
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/
#ifndef _HFI1_MMU_RB_H
#define _HFI1_MMU_RB_H
#include "hfi.h"
struct mmu_rb_node {
unsigned long addr;
unsigned long len;
unsigned long __last;
struct rb_node node;
struct list_head list;
};
/*
* NOTE: filter, insert, invalidate, and evict must not sleep. Only remove is
* allowed to sleep.
*/
struct mmu_rb_ops {
bool (*filter)(struct mmu_rb_node *node, unsigned long addr,
unsigned long len);
int (*insert)(void *ops_arg, struct mmu_rb_node *mnode);
void (*remove)(void *ops_arg, struct mmu_rb_node *mnode);
int (*invalidate)(void *ops_arg, struct mmu_rb_node *node);
int (*evict)(void *ops_arg, struct mmu_rb_node *mnode,
void *evict_arg, bool *stop);
};
int hfi1_mmu_rb_register(void *ops_arg, struct mm_struct *mm,
struct mmu_rb_ops *ops,
struct workqueue_struct *wq,
struct mmu_rb_handler **handler);
void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler);
int hfi1_mmu_rb_insert(struct mmu_rb_handler *handler,
struct mmu_rb_node *mnode);
void hfi1_mmu_rb_evict(struct mmu_rb_handler *handler, void *evict_arg);
void hfi1_mmu_rb_remove(struct mmu_rb_handler *handler,
struct mmu_rb_node *mnode);
bool hfi1_mmu_rb_remove_unless_exact(struct mmu_rb_handler *handler,
unsigned long addr, unsigned long len,
struct mmu_rb_node **rb_node);
#endif /* _HFI1_MMU_RB_H */