The history of pageAlloc using 's' as a receiver are lost to the depths
of time (perhaps it used to be called summary?), but it doesn't make
much sense anymore. Rename it to 'p'.
Generated with:
$ cd src/runtime
$ grep -R -b "func (s \*pageAlloc" . | awk -F : '{ print $1 ":#" $2+6 }' | xargs -n 1 -I {} env GOROOT=$(pwd)/../../ gorename -offset {} -to p -v
$ grep -R -b "func (s \*pageAlloc" . | awk -F : '{ print $1 ":#" $2+6 }' | xargs -n 1 -I {} env GOROOT=$(pwd)/../../ GOARCH=386 gorename -offset {} -to p -v
$ GOROOT=$(pwd)/../../ gorename -offset mpagecache.go:#2397 -to p -v
($2+6 to advance past "func (".)
Plus manual comment fixups.
Change-Id: I2d521a1cbf6ebe2ef6aae92e654bfc33c63d1aa9
Reviewed-on: https://go-review.googlesource.com/c/go/+/250517
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Apparently macOS/ARM64 has 47-bit addresses, instead of 33-bit as
on ios/ARM64. Enable more address bits.
Updates #38485.
Change-Id: I8aa64ba22a3933e3d9c4fffd17d902b5f31c30e3
Reviewed-on: https://go-review.googlesource.com/c/go/+/256918
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Currently the page allocator bitmap is implemented as a single giant
memory mapping which is reserved at init time and committed as needed.
This causes problems on systems that don't handle large uncommitted
mappings well, or institute low virtual address space defaults as a
memory limiting mechanism.
This change modifies the implementation of the page allocator bitmap
away from a directly-mapped set of bytes to a sparse array in same vein
as mheap.arenas. This will hurt performance a little but the biggest
gains are from the lockless allocation possible with the page allocator,
so the impact of this extra layer of indirection should be minimal.
In fact, this is exactly what we see:
https://perf.golang.org/search?q=upload:20191125.5
This reduces the amount of mapped (PROT_NONE) memory needed on systems
with 48-bit address spaces to ~600 MiB down from almost 9 GiB. The bulk
of this remaining memory is used by the summaries.
Go processes with 32-bit address spaces now always commit to 128 KiB of
memory for the bitmap. Previously it would only commit the pages in the
bitmap which represented the range of addresses (lowest address to
highest address, even if there are unused regions in that range) used by
the heap.
Updates #35568.
Updates #35451.
Change-Id: I0ff10380156568642b80c366001eefd0a4e6c762
Reviewed-on: https://go-review.googlesource.com/c/go/+/207497
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This change adds a new bitmap-based allocator to the runtime with tests.
It does not yet integrate the page allocator into the runtime and thus
this change is almost purely additive.
Updates #35112.
Change-Id: Ic3d024c28abee8be8797d3918116a80f901cc2bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/190622
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This change is the first of a series of changes which replace the
current page allocator (which is based on the contents of mgclarge.go
and some of mheap.go) with one based on free/used bitmaps.
It adds in the key constants for the page allocator as well as a comment
describing the implementation.
Updates #35112.
Change-Id: I839d3a07f46842ad379701d27aa691885afdba63
Reviewed-on: https://go-review.googlesource.com/c/go/+/190619
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Michael Pratt
Cherry Zhang
Michael Anthony Knyszek