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[PATCH 16/24] linux-user: Use page_find_range_empty for mmap_find_vma_re
From: |
Richard Henderson |
Subject: |
[PATCH 16/24] linux-user: Use page_find_range_empty for mmap_find_vma_reserved |
Date: |
Fri, 30 Jun 2023 15:21:51 +0200 |
Use the interval tree to find empty space, rather than
probing each page in turn.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/mmap.c | 46 ++++++----------------------------------------
1 file changed, 6 insertions(+), 40 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index e332555dd2..6ecdf9e56d 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -317,49 +317,15 @@ unsigned long last_brk;
static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
abi_ulong align)
{
- abi_ulong addr, end_addr, incr = qemu_host_page_size;
- int prot;
- bool looped = false;
+ target_ulong ret;
- if (size > reserved_va) {
- return (abi_ulong)-1;
+ ret = page_find_range_empty(start, reserved_va, size, align);
+ if (ret == -1 && start > mmap_min_addr) {
+ /* Restart at the beginning of the address space. */
+ ret = page_find_range_empty(mmap_min_addr, start - 1, size, align);
}
- /* Note that start and size have already been aligned by mmap_find_vma. */
-
- end_addr = start + size;
- if (start > reserved_va - size) {
- /* Start at the top of the address space. */
- end_addr = ((reserved_va + 1 - size) & -align) + size;
- looped = true;
- }
-
- /* Search downward from END_ADDR, checking to see if a page is in use. */
- addr = end_addr;
- while (1) {
- addr -= incr;
- if (addr > end_addr) {
- if (looped) {
- /* Failure. The entire address space has been searched. */
- return (abi_ulong)-1;
- }
- /* Re-start at the top of the address space. */
- addr = end_addr = ((reserved_va + 1 - size) & -align) + size;
- looped = true;
- } else {
- prot = page_get_flags(addr);
- if (prot) {
- /* Page in use. Restart below this page. */
- addr = end_addr = ((addr - size) & -align) + size;
- } else if (addr && addr + size == end_addr) {
- /* Success! All pages between ADDR and END_ADDR are free. */
- if (start == mmap_next_start) {
- mmap_next_start = addr;
- }
- return addr;
- }
- }
- }
+ return ret;
}
/*
--
2.34.1
- [PATCH 05/24] linux-user: Split TARGET_PROT_* out of syscall_defs.h, (continued)
- [PATCH 05/24] linux-user: Split TARGET_PROT_* out of syscall_defs.h, Richard Henderson, 2023/06/30
- [PATCH 08/24] bsd-user: Use page_check_range_empty for MAP_EXCL, Richard Henderson, 2023/06/30
- [PATCH 11/24] linux-user: Widen target_mmap offset argument to off_t, Richard Henderson, 2023/06/30
- [PATCH 12/24] linux-user: Rewrite target_mprotect, Richard Henderson, 2023/06/30
- [PATCH 09/24] linux-user: Implement MAP_FIXED_NOREPLACE, Richard Henderson, 2023/06/30
- [PATCH 10/24] linux-user: Split out target_to_host_prot, Richard Henderson, 2023/06/30
- [PATCH 14/24] accel/tcg: Introduce page_find_range_empty, Richard Henderson, 2023/06/30
- [PATCH 13/24] linux-user: Rewrite mmap_frag, Richard Henderson, 2023/06/30
- [PATCH 18/24] linux-user: Rewrite mmap_reserve, Richard Henderson, 2023/06/30
- [PATCH 15/24] bsd-user: Use page_find_range_empty for mmap_find_vma_reserved, Richard Henderson, 2023/06/30
- [PATCH 16/24] linux-user: Use page_find_range_empty for mmap_find_vma_reserved,
Richard Henderson <=
- [PATCH 17/24] linux-user: Use 'last' instead of 'end' in target_mmap, Richard Henderson, 2023/06/30
- [PATCH 20/24] linux-user: Simplify target_munmap, Richard Henderson, 2023/06/30
- [PATCH 21/24] accel/tcg: Accept more page flags in page_check_range, Richard Henderson, 2023/06/30
- [PATCH 19/24] linux-user: Rename mmap_reserve to mmap_reserve_or_unmap, Richard Henderson, 2023/06/30
- [PATCH 22/24] accel/tcg: Return bool from page_check_range, Richard Henderson, 2023/06/30
- [PATCH 23/24] linux-user: Remove can_passthrough_madvise, Richard Henderson, 2023/06/30
- [PATCH 24/24] linux-user: Simplify target_madvise, Richard Henderson, 2023/06/30