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Re: [Qemu-devel] [PATCH v1 4/6] mem: concenter the root of each AddressS
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH v1 4/6] mem: concenter the root of each AddressSpaceDispatch |
Date: |
Wed, 29 May 2013 09:03:47 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 |
Il 29/05/2013 04:11, Liu Ping Fan ha scritto:
> From: Liu Ping Fan <address@hidden>
>
> All of AddressSpaceDispatch's roots are part of dispatch context,
> along with cur_map_nodes, cur_phys_sections, and we should walk
> through AddressSpaceDispatchs in the same dispatch context, ie
> the same memory topology. Concenter the roots, so we can switch
> to next more easily.
>
> Signed-off-by: Liu Ping Fan <address@hidden>
> ---
> exec.c | 48 ++++++++++++++++++++++++++++++++++++---
> include/exec/memory-internal.h | 2 +-
> 2 files changed, 45 insertions(+), 5 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index eb69a98..315960d 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -49,6 +49,7 @@
> #include "translate-all.h"
>
> #include "exec/memory-internal.h"
> +#include "qemu/bitops.h"
>
> //#define DEBUG_SUBPAGE
>
> @@ -95,6 +96,7 @@ typedef struct AllocInfo {
> /* Only used for release purpose */
> Node *map;
> MemoryRegionSection *sections;
> + PhysPageEntry *roots;
> } AllocInfo;
I wouldn't put it here. I would put it in AddressSpaceDispatch (as
next_phys_map/next_sections/next_nodes: initialize
next_sections/next_nodes in the "begin" hook, switch under seqlock in
the "commit" hook).
This requires refcounting AllocInfo, but it removes the need for the
->idx indirection and the id management.
Paolo
> /* For performance, fetch page map related pointers directly, other than
> @@ -102,10 +104,12 @@ typedef struct AllocInfo {
> */
> static MemoryRegionSection *cur_phys_sections;
> static Node *cur_map_nodes;
> +static PhysPageEntry *cur_roots;
> static AllocInfo *cur_alloc_info;
>
> static MemoryRegionSection *next_phys_sections;
> static Node *next_map_nodes;
> +static PhysPageEntry *next_roots;
> static AllocInfo *next_alloc_info;
>
> #define PHYS_MAP_NODE_NIL (((uint16_t)~0) >> 1)
> @@ -191,12 +195,13 @@ static void phys_page_set(AddressSpaceDispatch *d,
> /* Wildly overreserve - it doesn't matter much. */
> phys_map_node_reserve(3 * P_L2_LEVELS);
>
> - phys_page_set_level(&d->phys_map, &index, &nb, leaf, P_L2_LEVELS - 1);
> + phys_page_set_level(&next_roots[d->idx], &index, &nb, leaf,
> + P_L2_LEVELS - 1);
> }
>
> static MemoryRegionSection *phys_page_find(AddressSpaceDispatch *d, hwaddr
> index, bool cur)
> {
> - PhysPageEntry lp = d->phys_map;
> + PhysPageEntry lp;
> PhysPageEntry *p;
> int i;
> Node *map_nodes;
> @@ -205,9 +210,11 @@ static MemoryRegionSection
> *phys_page_find(AddressSpaceDispatch *d, hwaddr index
> if (likely(cur)) {
> map_nodes = cur_map_nodes;
> sections = cur_phys_sections;
> + lp = cur_roots[d->idx];
> } else {
> map_nodes = next_map_nodes;
> sections = next_phys_sections;
> + lp = next_roots[d->idx];
> }
> for (i = P_L2_LEVELS - 1; i >= 0 && !lp.is_leaf; i--) {
> if (lp.ptr == PHYS_MAP_NODE_NIL) {
> @@ -1729,7 +1736,8 @@ static void mem_begin(MemoryListener *listener)
> {
> AddressSpaceDispatch *d = container_of(listener, AddressSpaceDispatch,
> listener);
>
> - d->phys_map.ptr = PHYS_MAP_NODE_NIL;
> + next_roots[d->idx] = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL,
> + is_leaf = 0 };
> }
>
> static void core_begin(MemoryListener *listener)
> @@ -1737,6 +1745,7 @@ static void core_begin(MemoryListener *listener)
> uint16_t n;
>
> next_alloc_info = g_malloc0(sizeof(AllocInfo));
> + next_roots = g_malloc0(2048*sizeof(PhysPageEntry));
> n = dummy_section(&io_mem_unassigned);
> assert(phys_section_unassigned == n);
> n = dummy_section(&io_mem_notdirty);
> @@ -1752,6 +1761,7 @@ static void release_dispatch_map(AllocInfo *info)
> phys_sections_clear(info->phys_sections_nb, info->sections);
> g_free(info->map);
> g_free(info->sections);
> + g_free(info->roots);
> g_free(info);
> }
>
> @@ -1765,6 +1775,7 @@ static void core_commit(MemoryListener *listener)
> AllocInfo *info = cur_alloc_info;
> info->map = cur_map_nodes;
> info->sections = cur_phys_sections;
> + info->roots = cur_roots;
>
> /* Fix me, in future, will be protected by wr seqlock when in parellel
> * with reader
> @@ -1772,6 +1783,7 @@ static void core_commit(MemoryListener *listener)
> cur_map_nodes = next_map_nodes;
> cur_phys_sections = next_phys_sections;
> cur_alloc_info = next_alloc_info;
> + cur_roots = next_roots;
>
> /* since each CPU stores ram addresses in its TLB cache, we must
> reset the modified entries */
> @@ -1826,11 +1838,36 @@ static MemoryListener io_memory_listener = {
> .priority = 0,
> };
>
> +static MemoryListener tcg_memory_listener = {
> + .commit = tcg_commit,
> +};
Rebase artifact?
> +#define MAX_IDX (1<<15)
> +static unsigned long *address_space_id_map;
> +static QemuMutex id_lock;
> +
> +static void address_space_release_id(int16_t idx)
> +{
> + qemu_mutex_lock(&id_lock);
> + clear_bit(idx, address_space_id_map);
> + qemu_mutex_unlock(&id_lock);
> +}
> +
> +static int16_t address_space_alloc_id()
> +{
> + unsigned long idx;
> +
> + qemu_mutex_lock(&id_lock);
> + idx = find_first_zero_bit(address_space_id_map, MAX_IDX/BITS_PER_LONG);
> + set_bit(idx, address_space_id_map);
> + qemu_mutex_unlock(&id_lock);
> +}
> +
> void address_space_init_dispatch(AddressSpace *as)
> {
> AddressSpaceDispatch *d = g_new(AddressSpaceDispatch, 1);
>
> - d->phys_map = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL, .is_leaf = 0
> };
> + d->idx = address_space_alloc_id();
> d->listener = (MemoryListener) {
> .begin = mem_begin,
> .region_add = mem_add,
> @@ -1845,6 +1882,7 @@ void address_space_destroy_dispatch(AddressSpace *as)
> {
> AddressSpaceDispatch *d = as->dispatch;
>
> + address_space_release_id(d->idx);
> memory_listener_unregister(&d->listener);
> g_free(d);
> as->dispatch = NULL;
> @@ -1852,6 +1890,8 @@ void address_space_destroy_dispatch(AddressSpace *as)
>
> static void memory_map_init(void)
> {
> + qemu_mutex_init(&id_lock);
> + address_space_id_map = g_malloc0(MAX_IDX/BITS_PER_BYTE);
> system_memory = g_malloc(sizeof(*system_memory));
> memory_region_init(system_memory, "system", INT64_MAX);
> address_space_init(&address_space_memory, system_memory, "memory");
> diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h
> index 799c02a..54a3635 100644
> --- a/include/exec/memory-internal.h
> +++ b/include/exec/memory-internal.h
> @@ -36,7 +36,7 @@ struct AddressSpaceDispatch {
> /* This is a multi-level map on the physical address space.
> * The bottom level has pointers to MemoryRegionSections.
> */
> - PhysPageEntry phys_map;
> + int16_t idx;
> MemoryListener listener;
> };
>
>
[Qemu-devel] [PATCH v1 5/6] mem: make dispatch path satify rcu style, Liu Ping Fan, 2013/05/28
[Qemu-devel] [PATCH v1 6/6] mem: change tcg code to rcu style, Liu Ping Fan, 2013/05/28