YJIT: Use the system page size when the code page size is too small #7267
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Previously on ARM64 Linux systems that use 64 KiB pages (`CONFIG_ARM64_64K_PAGES=y`), YJIT was panicking on boot due to a failed assertion. The assertion was making sure that code GC can free the last code page that YJIT manages without freeing unrelated memory. YJIT prefers picking 16 KiB as the granularity at which to free code memory, but when the system can only free at 64 KiB granularity, that is not possible. The fix is to use the system page size as the code page size when the system page size is 64 KiB. Continue to use 16 KiB as the code page size on common systems that use 16/4 KiB pages. Add asserts to code_gc() and free_page() about code GC's assumptions. Fixes [Bug #19400]
maximecb
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…Backport #19400] YJIT: Use the system page size when the code page size is too small (ruby#7267) Previously on ARM64 Linux systems that use 64 KiB pages (`CONFIG_ARM64_64K_PAGES=y`), YJIT was panicking on boot due to a failed assertion. The assertion was making sure that code GC can free the last code page that YJIT manages without freeing unrelated memory. YJIT prefers picking 16 KiB as the granularity at which to free code memory, but when the system can only free at 64 KiB granularity, that is not possible. The fix is to use the system page size as the code page size when the system page size is 64 KiB. Continue to use 16 KiB as the code page size on common systems that use 16/4 KiB pages. Add asserts to code_gc() and free_page() about code GC's assumptions. Fixes [Bug #19400] --- yjit/src/asm/mod.rs | 78 ++++++++++++++++++++++++++++++++------------------ yjit/src/codegen.rs | 2 -- yjit/src/virtualmem.rs | 13 +++++++++ 3 files changed, 63 insertions(+), 30 deletions(-) YJIT: Fix assertion for partially mapped last pages (ruby#7337) Follows up [Bug #19400] --- test/ruby/test_yjit.rb | 19 +++++++++++++++++++ yjit/src/asm/mod.rs | 2 +- yjit/src/virtualmem.rs | 18 +++++++++++++----- 3 files changed, 33 insertions(+), 6 deletions(-)
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Previously on ARM64 Linux systems that use 64 KiB pages
(
CONFIG_ARM64_64K_PAGES=y), YJIT was panicking on boot due to a failedassertion.
The assertion was making sure that code GC can free the last code page
that YJIT manages without freeing unrelated memory. YJIT prefers picking
16 KiB as the granularity at which to free code memory, but when the
system can only free at 64 KiB granularity, that is not possible.
The fix is to use the system page size as the code page size when the
system page size is 64 KiB. Continue to use 16 KiB as the code page size
on common systems that use 16/4 KiB pages.
Add asserts to code_gc() and free_page() about code GC's assumptions.
Fixes [Bug #19400]