From: "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>
To: qemu-devel@nongnu.org
Cc: quintela@redhat.com, yury-kotov@yandex-team.ru,
richardw.yang@linux.intel.com, marcandre.lureau@redhat.com,
ivanren@tencent.com
Subject: [Qemu-devel] [PULL 19/33] migration/postcopy: make PostcopyDiscardState a static variable
Date: Thu, 15 Aug 2019 17:34:50 +0100 [thread overview]
Message-ID: <20190815163504.18937-20-dgilbert@redhat.com> (raw)
In-Reply-To: <20190815163504.18937-1-dgilbert@redhat.com>
From: Wei Yang <richardw.yang@linux.intel.com>
In postcopy-ram.c, we provide three functions to discard certain
RAMBlock range:
* postcopy_discard_send_init()
* postcopy_discard_send_range()
* postcopy_discard_send_finish()
Currently, we allocate/deallocate PostcopyDiscardState for each RAMBlock
on sending discard information to destination. This is not necessary and
the same data area could be reused for each RAMBlock.
This patch defines PostcopyDiscardState a static variable. By doing so:
1) avoid memory allocation and deallocation to the system
2) avoid potential failure of memory allocation
3) hide some details for their users
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190724010721.2146-1-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
migration/postcopy-ram.c | 70 +++++++++++++++++-----------------------
migration/postcopy-ram.h | 13 +++-----
migration/ram.c | 30 +++++++----------
3 files changed, 46 insertions(+), 67 deletions(-)
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 9faacacc9e..2cb1a69752 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -1377,22 +1377,16 @@ void postcopy_fault_thread_notify(MigrationIncomingState *mis)
* asking to discard individual ranges.
*
* @ms: The current migration state.
- * @offset: the bitmap offset of the named RAMBlock in the migration
- * bitmap.
+ * @offset: the bitmap offset of the named RAMBlock in the migration bitmap.
* @name: RAMBlock that discards will operate on.
- *
- * returns: a new PDS.
*/
-PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
- const char *name)
+static PostcopyDiscardState pds = {0};
+void postcopy_discard_send_init(MigrationState *ms, const char *name)
{
- PostcopyDiscardState *res = g_malloc0(sizeof(PostcopyDiscardState));
-
- if (res) {
- res->ramblock_name = name;
- }
-
- return res;
+ pds.ramblock_name = name;
+ pds.cur_entry = 0;
+ pds.nsentwords = 0;
+ pds.nsentcmds = 0;
}
/**
@@ -1401,30 +1395,29 @@ PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
* be sent later.
*
* @ms: Current migration state.
- * @pds: Structure initialised by postcopy_discard_send_init().
* @start,@length: a range of pages in the migration bitmap in the
* RAM block passed to postcopy_discard_send_init() (length=1 is one page)
*/
-void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
- unsigned long start, unsigned long length)
+void postcopy_discard_send_range(MigrationState *ms, unsigned long start,
+ unsigned long length)
{
size_t tp_size = qemu_target_page_size();
/* Convert to byte offsets within the RAM block */
- pds->start_list[pds->cur_entry] = start * tp_size;
- pds->length_list[pds->cur_entry] = length * tp_size;
- trace_postcopy_discard_send_range(pds->ramblock_name, start, length);
- pds->cur_entry++;
- pds->nsentwords++;
+ pds.start_list[pds.cur_entry] = start * tp_size;
+ pds.length_list[pds.cur_entry] = length * tp_size;
+ trace_postcopy_discard_send_range(pds.ramblock_name, start, length);
+ pds.cur_entry++;
+ pds.nsentwords++;
- if (pds->cur_entry == MAX_DISCARDS_PER_COMMAND) {
+ if (pds.cur_entry == MAX_DISCARDS_PER_COMMAND) {
/* Full set, ship it! */
qemu_savevm_send_postcopy_ram_discard(ms->to_dst_file,
- pds->ramblock_name,
- pds->cur_entry,
- pds->start_list,
- pds->length_list);
- pds->nsentcmds++;
- pds->cur_entry = 0;
+ pds.ramblock_name,
+ pds.cur_entry,
+ pds.start_list,
+ pds.length_list);
+ pds.nsentcmds++;
+ pds.cur_entry = 0;
}
}
@@ -1433,24 +1426,21 @@ void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
* bitmap code. Sends any outstanding discard messages, frees the PDS
*
* @ms: Current migration state.
- * @pds: Structure initialised by postcopy_discard_send_init().
*/
-void postcopy_discard_send_finish(MigrationState *ms, PostcopyDiscardState *pds)
+void postcopy_discard_send_finish(MigrationState *ms)
{
/* Anything unsent? */
- if (pds->cur_entry) {
+ if (pds.cur_entry) {
qemu_savevm_send_postcopy_ram_discard(ms->to_dst_file,
- pds->ramblock_name,
- pds->cur_entry,
- pds->start_list,
- pds->length_list);
- pds->nsentcmds++;
+ pds.ramblock_name,
+ pds.cur_entry,
+ pds.start_list,
+ pds.length_list);
+ pds.nsentcmds++;
}
- trace_postcopy_discard_send_finish(pds->ramblock_name, pds->nsentwords,
- pds->nsentcmds);
-
- g_free(pds);
+ trace_postcopy_discard_send_finish(pds.ramblock_name, pds.nsentwords,
+ pds.nsentcmds);
}
/*
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index 9d55536fd1..9c8bd2bae0 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -43,10 +43,8 @@ int postcopy_ram_prepare_discard(MigrationIncomingState *mis);
/*
* Called at the start of each RAMBlock by the bitmap code.
- * Returns a new PDS
*/
-PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
- const char *name);
+void postcopy_discard_send_init(MigrationState *ms, const char *name);
/*
* Called by the bitmap code for each chunk to discard.
@@ -55,15 +53,14 @@ PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
* @start,@length: a range of pages in the migration bitmap in the
* RAM block passed to postcopy_discard_send_init() (length=1 is one page)
*/
-void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
- unsigned long start, unsigned long length);
+void postcopy_discard_send_range(MigrationState *ms, unsigned long start,
+ unsigned long length);
/*
* Called at the end of each RAMBlock by the bitmap code.
- * Sends any outstanding discard messages, frees the PDS.
+ * Sends any outstanding discard messages.
*/
-void postcopy_discard_send_finish(MigrationState *ms,
- PostcopyDiscardState *pds);
+void postcopy_discard_send_finish(MigrationState *ms);
/*
* Place a page (from) at (host) efficiently
diff --git a/migration/ram.c b/migration/ram.c
index a44e9c0abc..f428639af5 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2850,12 +2850,9 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms)
* with the dirtymap; so a '1' means it's either dirty or unsent.
*
* @ms: current migration state
- * @pds: state for postcopy
* @block: RAMBlock to discard
*/
-static int postcopy_send_discard_bm_ram(MigrationState *ms,
- PostcopyDiscardState *pds,
- RAMBlock *block)
+static int postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block)
{
unsigned long end = block->used_length >> TARGET_PAGE_BITS;
unsigned long current;
@@ -2876,7 +2873,7 @@ static int postcopy_send_discard_bm_ram(MigrationState *ms,
} else {
discard_length = zero - one;
}
- postcopy_discard_send_range(ms, pds, one, discard_length);
+ postcopy_discard_send_range(ms, one, discard_length);
current = one + discard_length;
}
@@ -2902,16 +2899,15 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
int ret;
RAMBLOCK_FOREACH_NOT_IGNORED(block) {
- PostcopyDiscardState *pds =
- postcopy_discard_send_init(ms, block->idstr);
+ postcopy_discard_send_init(ms, block->idstr);
/*
* Postcopy sends chunks of bitmap over the wire, but it
* just needs indexes at this point, avoids it having
* target page specific code.
*/
- ret = postcopy_send_discard_bm_ram(ms, pds, block);
- postcopy_discard_send_finish(ms, pds);
+ ret = postcopy_send_discard_bm_ram(ms, block);
+ postcopy_discard_send_finish(ms);
if (ret) {
return ret;
}
@@ -2934,11 +2930,9 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
* @unsent_pass: if true we need to canonicalize partially unsent host pages
* otherwise we need to canonicalize partially dirty host pages
* @block: block that contains the page we want to canonicalize
- * @pds: state for postcopy
*/
static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
- RAMBlock *block,
- PostcopyDiscardState *pds)
+ RAMBlock *block)
{
RAMState *rs = ram_state;
unsigned long *bitmap = block->bmap;
@@ -3018,8 +3012,7 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
* (any partially sent pages were already discarded
* by the previous unsent_pass)
*/
- postcopy_discard_send_range(ms, pds, fixup_start_addr,
- host_ratio);
+ postcopy_discard_send_range(ms, fixup_start_addr, host_ratio);
}
/* Clean up the bitmap */
@@ -3062,18 +3055,17 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
*/
static int postcopy_chunk_hostpages(MigrationState *ms, RAMBlock *block)
{
- PostcopyDiscardState *pds =
- postcopy_discard_send_init(ms, block->idstr);
+ postcopy_discard_send_init(ms, block->idstr);
/* First pass: Discard all partially sent host pages */
- postcopy_chunk_hostpages_pass(ms, true, block, pds);
+ postcopy_chunk_hostpages_pass(ms, true, block);
/*
* Second pass: Ensure that all partially dirty host pages are made
* fully dirty.
*/
- postcopy_chunk_hostpages_pass(ms, false, block, pds);
+ postcopy_chunk_hostpages_pass(ms, false, block);
- postcopy_discard_send_finish(ms, pds);
+ postcopy_discard_send_finish(ms);
return 0;
}
--
2.21.0
next prev parent reply other threads:[~2019-08-15 16:40 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-15 16:34 [Qemu-devel] [PULL 00/33] migration queue Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 01/33] migration: Add error_desc for file channel errors Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 02/33] hw/net: fix vmxnet3 live migration Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 03/33] migration: consolidate time info into populate_time_info Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 04/33] migration/postcopy: the valid condition is one less then end Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 05/33] migration/postcopy: break the loop when there is no more page to discard Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 06/33] migration/postcopy: discard_length must not be 0 Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 07/33] migration/postcopy: reduce one operation to calculate fixup_start_addr Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 08/33] migration/postcopy: do_fixup is true when host_offset is non-zero Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 09/33] migration/savevm: flush file for iterable_only case Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 10/33] migration/savevm: split qemu_savevm_state_complete_precopy() into two parts Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 11/33] migration/savevm: move non SaveStateEntry condition check out of iteration Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 12/33] migration/postcopy: PostcopyState is already set in loadvm_postcopy_handle_advise() Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 13/33] migration/postcopy: start_postcopy could be true only when migrate_postcopy() return true Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 14/33] migration: use migration_in_postcopy() to check POSTCOPY_ACTIVE Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 15/33] migration: just pass RAMBlock is enough Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 16/33] migration: equation is more proper than and to check LOADVM_QUIT Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 17/33] migration: return -EINVAL directly when version_id mismatch Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 18/33] migration: extract ram_load_precopy Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` Dr. David Alan Gilbert (git) [this message]
2019-08-15 16:34 ` [Qemu-devel] [PULL 20/33] migration/postcopy: simplify calculation of run_start and fixup_start_addr Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 21/33] migration/postcopy: use QEMU_IS_ALIGNED to replace host_offset Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 22/33] hmp: Remove migration capabilities from "info migrate" Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 23/33] migration: remove unused field bytes_xfer Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 24/33] migration: always initialise ram_counters for a new migration Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 25/33] migration: add qemu_file_update_transfer interface Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 26/33] migration: add speed limit for multifd migration Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 27/33] migration: update ram_counters for multifd sync packet Dr. David Alan Gilbert (git)
2019-08-15 16:34 ` [Qemu-devel] [PULL 28/33] migration: rename migration_bitmap_sync_range to ramblock_sync_dirty_bitmap Dr. David Alan Gilbert (git)
2019-08-15 16:35 ` [Qemu-devel] [PULL 29/33] migration/postcopy: use mis->bh instead of allocating a QEMUBH Dr. David Alan Gilbert (git)
2019-08-15 16:35 ` [Qemu-devel] [PULL 30/33] qemu-file: move qemu_{get, put}_counted_string() declarations Dr. David Alan Gilbert (git)
2019-08-15 16:35 ` [Qemu-devel] [PULL 31/33] migration: Add traces for multifd terminate threads Dr. David Alan Gilbert (git)
2019-08-15 16:35 ` [Qemu-devel] [PULL 32/33] migration: Make global sem_sync semaphore by channel Dr. David Alan Gilbert (git)
2019-08-15 16:35 ` [Qemu-devel] [PULL 33/33] migration: add some multifd traces Dr. David Alan Gilbert (git)
2019-08-16 12:58 ` [Qemu-devel] [PULL 00/33] migration queue Peter Maydell
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