On Sun, Mar 29, 2020 at 8:01 PM Waldek Kozaczuk <[email protected]> wrote:
> I have just sent two new V5 patches. One extra question below in case that > might be an issue as well. > > On Sun, Mar 29, 2020 at 12:28 PM Waldek Kozaczuk <[email protected]> > wrote: > >> +static void* malloc_large(size_t size, size_t alignment, bool block = >> true, bool contiguous = true) >> >>> { >>>> auto requested_size = size; >>>> size_t offset; >>>> @@ -835,6 +843,14 @@ static void* malloc_large(size_t size, size_t >>>> alignment, bool block = true) >>>> size += offset; >>>> size = align_up(size, page_size); >>>> >>>> + // Use mmap if requested memory greater than "huge page" size >>>> + // and does not need to be contiguous >>>> + if (size >= mmu::huge_page_size && !contiguous) { >>>> + void* obj = mapped_malloc_large(size, offset); >>>> + trace_memory_malloc_large(obj, requested_size, size, >>>> alignment); >>>> + return obj; >>>> + } >>>> + >>>> >>> Not sure if above and below when we call mapped_malloc_large() we need > to do something extra if (alignment > page_size). What do you think? > It's a good question. You're right, but I don't know if this even worked correctly in the past. However, importantly, in the functions alloc_phys_contiguous_aligned() and posix_memalign(), we end the function by asserting that whatever underlying functions we called, the returned pointer has the desired alignment. So if we have a bug in this case (and I think we do) it will at least cause an assertion failure - and not silently return wrongly aligned memory. I'll commit your code with this issue, and we can address it later. I doubt anybody actually need such huge alignments in real-world applications (what's the point?). > while (true) { >>>> WITH_LOCK(free_page_ranges_lock) { >>>> reclaimer_thread.wait_for_minimum_memory(); >>>> @@ -842,7 +858,7 @@ static void* malloc_large(size_t size, size_t >>>> alignment, bool block = true) >>>> if (alignment > page_size) { >>>> ret_header = free_page_ranges.alloc_aligned(size, >>>> page_size, alignment); >>>> } else { >>>> - ret_header = free_page_ranges.alloc(size); >>>> + ret_header = free_page_ranges.alloc(size, contiguous); >>>> } >>>> if (ret_header) { >>>> on_alloc(size); >>>> @@ -850,6 +866,10 @@ static void* malloc_large(size_t size, size_t >>>> alignment, bool block = true) >>>> obj += offset; >>>> trace_memory_malloc_large(obj, requested_size, size, >>>> alignment); >>>> return obj; >>>> + } else if (!contiguous) { >>>> + // If we failed to get contiguous memory allocation and >>>> + // the caller does not require one let us use >>>> map-based allocation >>>> + break; >>>> } >>>> if (block) >>>> reclaimer_thread.wait_for_memory(size); >>>> @@ -857,6 +877,10 @@ static void* malloc_large(size_t size, size_t >>>> alignment, bool block = true) >>>> return nullptr; >>>> } >>>> } >>>> + >>>> + void* obj = mapped_malloc_large(size, offset); >>>> + trace_memory_malloc_large(obj, requested_size, size, alignment); >>>> + return obj; >>>> >>> >>> nipick: wouldn't it be clearer to put this code where you have the >>> "break" above (instead of the "break"), instead of here? >>> >>> } >>>> >>>> void shrinker::deactivate_shrinker() >>>> @@ -1072,9 +1096,11 @@ static void free_large(void* obj) >>>> >>>> static unsigned large_object_size(void *obj) >>>> { >>>> + auto original_obj = obj; >>>> obj = align_down(obj - 1, page_size); >>>> >>> + size_t offset = reinterpret_cast<uint64_t>(original_obj) - >>>> reinterpret_cast<uint64_t>(obj); >>>> >>> auto header = static_cast<page_range*>(obj); >>>> - return header->size; >>>> + return header->size - offset; >>>> >>> } >>>> >>> >>> I wonder if just this change explains >>> https://github.com/cloudius-systems/osv/issues/784 and we should close >>> that issue. >>> But don't feel an expert enough in this issue to say... >>> >>> >>>> namespace page_pool { >>>> @@ -1692,7 +1718,7 @@ static inline void* std_malloc(size_t size, >>>> size_t alignment) >>>> memory::alloc_page()); >>>> trace_memory_malloc_page(ret, size, mmu::page_size, alignment); >>>> } else { >>>> - ret = memory::malloc_large(size, alignment); >>>> + ret = memory::malloc_large(size, alignment, true, false); >>>> } >>>> memory::tracker_remember(ret, size); >>>> return ret; >>>> @@ -1714,6 +1740,14 @@ void* calloc(size_t nmemb, size_t size) >>>> >>>> static size_t object_size(void *object) >>>> { >>>> + if (!mmu::is_linear_mapped(object, 0)) { >>>> + auto original_object = object; >>>> + object = align_down(object - 1, mmu::page_size); >>>> + size_t offset = reinterpret_cast<uint64_t>(original_object) - >>>> reinterpret_cast<uint64_t>(object); >>>> + size_t* ret_header = static_cast<size_t*>(object); >>>> + return *ret_header - offset; >>>> >>> >>> Can you just call large_object_size() here instead of duplicating its >>> code? >>> Just like you do below in the mmu::mem_area::main case? >>> >> The 3 lines of this code are identical so I will create a separate common >> function. But the last 2 are actually different as they reference size_t >> header vs page_header though it would most likely end up working the same. >> >>> >>> >>>> + } >>>> + >>>> switch (mmu::get_mem_area(object)) { >>>> case mmu::mem_area::main: >>>> return memory::large_object_size(object); >>>> @@ -1763,6 +1797,14 @@ void free(void* object) >>>> return; >>>> } >>>> memory::tracker_forget(object); >>>> + >>>> + if (!mmu::is_linear_mapped(object, 0)) { >>>> + object = align_down(object - 1, mmu::page_size); >>>> + size_t* ret_header = static_cast<size_t*>(object); >>>> + mmu::munmap(object, *ret_header); >>>> + return; >>>> >>> >>> Nitpick: would be nice to put this code in a function >>> mapped_free_large(), and put this >>> function next to mapped_malloc_large() which you already have - so a >>> reader can see >>> the two of them next to each other. >>> >>> + } >>>> + >>>> switch (mmu::get_mem_area(object)) { >>>> case mmu::mem_area::page: >>>> object = mmu::translate_mem_area(mmu::mem_area::page, >>>> @@ -1972,7 +2014,7 @@ void* alloc_phys_contiguous_aligned(size_t size, >>>> size_t align, bool block) >>>> assert(is_power_of_two(align)); >>>> // make use of the standard large allocator returning properly >>>> aligned >>>> // physically contiguous memory: >>>> - auto ret = malloc_large(size, align, block); >>>> + auto ret = malloc_large(size, align, block, true); >>>> assert (!(reinterpret_cast<uintptr_t>(ret) & (align - 1))); >>>> return ret; >>>> } >>>> diff --git a/modules/tests/Makefile b/modules/tests/Makefile >>>> index ce004339..10df022f 100644 >>>> --- a/modules/tests/Makefile >>>> +++ b/modules/tests/Makefile >>>> @@ -129,7 +129,7 @@ tests := tst-pthread.so misc-ramdisk.so tst-vblk.so >>>> tst-bsd-evh.so \ >>>> tst-sigaltstack.so tst-fread.so tst-tcp-cork.so tst-tcp-v6.so \ >>>> tst-calloc.so tst-crypt.so tst-non-fpic.so tst-small-malloc.so \ >>>> tst-mmx-fpu.so tst-getopt.so tst-getopt-pie.so tst-non-pie.so >>>> tst-semaphore.so \ >>>> - tst-elf-init.so >>>> + tst-elf-init.so tst-realloc.so >>>> # libstatic-thread-variable.so tst-static-thread-variable.so \ >>>> >>>> tests += testrunner.so >>>> diff --git a/tests/tst-realloc.cc b/tests/tst-realloc.cc >>>> new file mode 100644 >>>> index 00000000..49edfb7a >>>> --- /dev/null >>>> +++ b/tests/tst-realloc.cc >>>> @@ -0,0 +1,94 @@ >>>> +/* >>>> +* Copyright (C) 2020 Waldemar Kozaczuk >>>> +* >>>> +* This work is open source software, licensed under the terms of the >>>> +* BSD license as described in the LICENSE file in the top-level >>>> directory. >>>> +*/ >>>> + >>>> +#include <stdlib.h> >>>> +#include <string.h> >>>> +#include <cassert> >>>> +#include <iostream> >>>> + >>>> +extern "C" size_t malloc_usable_size (void *ptr); >>>> + >>>> +static void test_realloc(size_t original_size, size_t new_size) >>>> +{ >>>> + char data[11] = "0123456789"; >>>> + >>>> + void *original_buf = malloc(original_size); >>>> + assert(original_buf); >>>> + >>>> + char *buf = static_cast<char*>(original_buf); >>>> + for (size_t i = 0; i < original_size; i++) { >>>> + buf[i] = data[i % 10]; >>>> + } >>>> + >>>> + void *new_buf = realloc(original_buf, new_size); >>>> + assert(new_buf); >>>> + >>>> + auto expected_same_data_len = std::min(original_size, new_size); >>>> + buf = static_cast<char*>(new_buf); >>>> + for (size_t i = 0; i < expected_same_data_len; i++) { >>>> + assert(buf[i] == data[i % 10]); >>>> + } >>>> + >>>> + free(new_buf); >>>> + >>>> + std::cerr << "PASSED realloc() for original_size: " << >>>> original_size << ", new_size: " << new_size << std::endl; >>>> +} >>>> + >>>> +static void test_usable_size(size_t size, size_t expected_usable_size) >>>> +{ >>>> + void* ptr = malloc(size); >>>> + assert(expected_usable_size == malloc_usable_size(ptr)); >>>> + free(ptr); >>>> + >>>> + std::cerr << "PASSED malloc_usable_size() for size: " << size << >>>> std::endl; >>>> +} >>>> + >>>> +int main() >>>> +{ >>>> + test_realloc(1,2); >>>> + test_realloc(2,1); >>>> + >>>> + test_realloc(4,7); >>>> + test_realloc(7,4); >>>> + >>>> + test_realloc(63,128); >>>> + test_realloc(128,63); >>>> + >>>> + test_realloc(4000,5000); >>>> + test_realloc(5000,4000); >>>> + >>>> + test_realloc(4096,4096); >>>> + >>>> + test_realloc(0x100000,0x100000); >>>> + test_realloc(0x100000,0x100900); >>>> + test_realloc(0x100900,0x100000); >>>> + >>>> + test_realloc(0x200000,0x200000); >>>> + test_realloc(0x200000,0x300900); >>>> + test_realloc(0x300900,0x200000); >>>> + >>>> + test_realloc(0x600900,0x600000); >>>> + test_realloc(0x400000,0x600000); >>>> + test_realloc(0x600000,0x400900); >>>> + >>>> + void *buf = realloc(nullptr, 0); >>>> + assert(buf); >>>> + free(buf); >>>> + >>>> + buf = malloc(16); >>>> + assert(!realloc(buf, 0)); >>>> + >>>> + test_usable_size(1, 8); >>>> + test_usable_size(8, 8); >>>> + test_usable_size(67, 128); >>>> + test_usable_size(0x4010, 0x4FC0); >>>> + test_usable_size(0x100000, 0x100FC0); >>>> + test_usable_size(0x200000, 0x200FC0); >>>> + >>>> + std::cerr << "PASSED\n"; >>>> + return 0; >>>> +} >>>> \ No newline at end of file >>>> -- >>>> 2.20.1 >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "OSv Development" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/osv-dev/20200326183626.12013-1-jwkozaczuk%40gmail.com >>>> . >>>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "OSv Development" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/osv-dev/a71c97ed-0dbe-4570-b345-b046532a55aa%40googlegroups.com >> <https://groups.google.com/d/msgid/osv-dev/a71c97ed-0dbe-4570-b345-b046532a55aa%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups > "OSv Development" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/osv-dev/CAL9cFfPiQRW2RPAM9d6LnpkqE5Yz%2BCdBMrZ6O-vfvu_TXLhHTg%40mail.gmail.com > <https://groups.google.com/d/msgid/osv-dev/CAL9cFfPiQRW2RPAM9d6LnpkqE5Yz%2BCdBMrZ6O-vfvu_TXLhHTg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "OSv Development" group. 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