From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Subject: [Qemu-devel] [PATCH 21/22] memory: make cpu_physical_memory_sync_dirty_bitmap() fully atomic
Date: Thu, 26 Mar 2015 18:38:39 +0100 [thread overview]
Message-ID: <1427391520-29497-22-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1427391520-29497-1-git-send-email-pbonzini@redhat.com>
From: Stefan Hajnoczi <stefanha@redhat.com>
The fast path of cpu_physical_memory_sync_dirty_bitmap() directly
manipulates the dirty bitmap. Use atomic_xchg() to make the
test-and-clear atomic.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1417519399-3166-7-git-send-email-stefanha@redhat.com>
[Only do xchg on nonzero words. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
include/exec/ram_addr.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index b7357ac..c4e5624 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -220,12 +220,12 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest,
for (k = page; k < page + nr; k++) {
if (src[k]) {
+ unsigned long bits = atomic_xchg(&src[k], 0);
unsigned long new_dirty;
new_dirty = ~dest[k];
- dest[k] |= src[k];
- new_dirty &= src[k];
+ dest[k] |= bits;
+ new_dirty &= bits;
num_dirty += ctpopl(new_dirty);
- src[k] = 0;
}
}
} else {
--
2.3.3
next prev parent reply other threads:[~2015-03-26 17:39 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-26 17:38 [Qemu-devel] [PATCH 00/22] Dirty bitmap atomic access and optimizations Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 01/22] memory: add memory_region_ram_resize Paolo Bonzini
2015-03-28 18:58 ` Michael S. Tsirkin
2015-03-29 7:30 ` Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 02/22] acpi-build: remove dependency from ram_addr.h Paolo Bonzini
2015-03-28 18:58 ` Michael S. Tsirkin
2015-03-26 17:38 ` [Qemu-devel] [PATCH 03/22] memory: the only dirty memory flag for users is DIRTY_MEMORY_VGA Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 04/22] display: enable DIRTY_MEMORY_VGA tracking explicitly Paolo Bonzini
2015-04-20 13:11 ` Stefan Hajnoczi
2015-04-20 13:54 ` Paolo Bonzini
2015-04-22 9:12 ` Stefan Hajnoczi
2015-03-26 17:38 ` [Qemu-devel] [PATCH 05/22] memory: return bitmap from memory_region_is_logging Paolo Bonzini
2015-03-27 5:44 ` Fam Zheng
2015-03-27 6:01 ` Paolo Bonzini
2015-03-28 18:54 ` Michael S. Tsirkin
2015-03-29 7:33 ` Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 06/22] framebuffer: check memory_region_is_logging Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 07/22] ui/console: " Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 08/22] memory: track DIRTY_MEMORY_CODE in mr->dirty_log_mask Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 09/22] memory: return DIRTY_MEMORY_MIGRATION from memory_region_is_logging Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 10/22] ram_addr: tweaks to xen_modified_memory Paolo Bonzini
2015-03-28 19:04 ` Stefano Stabellini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 11/22] exec: simplify notdirty_mem_write Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 12/22] exec: use memory_region_is_logging to optimize dirty tracking Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 13/22] exec: pass client mask to cpu_physical_memory_set_dirty_range Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 14/22] exec: only check relevant bitmaps for cleanliness Paolo Bonzini
2015-03-27 6:10 ` Fam Zheng
2015-03-27 9:19 ` Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 15/22] memory: do not touch code dirty bitmap unless TCG is enabled Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 16/22] bitmap: add atomic set functions Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 17/22] bitmap: add atomic test and clear Paolo Bonzini
2015-03-27 6:37 ` Fam Zheng
2015-03-27 9:21 ` Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 18/22] memory: use atomic ops for setting dirty memory bits Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 19/22] migration: move dirty bitmap sync to ram_addr.h Paolo Bonzini
2015-03-26 17:38 ` [Qemu-devel] [PATCH 20/22] memory: replace cpu_physical_memory_reset_dirty() with test-and-clear Paolo Bonzini
2015-03-26 17:38 ` Paolo Bonzini [this message]
2015-03-26 17:38 ` [Qemu-devel] [PATCH 22/22] migration: run bitmap sync outside iothread lock Paolo Bonzini
2015-04-20 13:23 ` [Qemu-devel] [PATCH 00/22] Dirty bitmap atomic access and optimizations Stefan Hajnoczi
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