tequilaOS/platform_build_blueprint
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Remove unnecessary locking in fs

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osFs.acquire and osFs.release are surprisingly expensive, using a
combined 345.7s of runtime in an AOSP aosp_cf_x86_64_phone-userdebug
build.  They are used to ensure we don't use too many simultaneous
open files, but many of the functions they are called from don't
actually open a file.  Remove them from all the stat-based functions
(Exists, IsDir, IsSymlink, Lstat, Stat), and from ReadLink.  After
this change the time spent in acquire and release is effectively
zero.

Test: SOONG_PROFILE_CPU=/tmp/cpu.pprof m nothing
Change-Id: Ie5e22e33c61794354821f05ab79ceb4efc3b276c
This commit is contained in:
Colin Cross 2023-10-26 14:02:58 -07:00
parent 0065131f50
commit 098c09334f
1 changed files with 0 additions and 12 deletions
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12
pathtools/fs.go
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@ -204,8 +204,6 @@ func (fs *osFs) Open(name string) (ReaderAtSeekerCloser, error) {
} }
func (fs *osFs) Exists(name string) (bool, bool, error) { func (fs *osFs) Exists(name string) (bool, bool, error) {
fs.acquire()
defer fs.release()
stat, err := os.Stat(fs.toAbs(name)) stat, err := os.Stat(fs.toAbs(name))
if err == nil { if err == nil {
return true, stat.IsDir(), nil return true, stat.IsDir(), nil
@ -217,8 +215,6 @@ func (fs *osFs) Exists(name string) (bool, bool, error) {
} }
func (fs *osFs) IsDir(name string) (bool, error) { func (fs *osFs) IsDir(name string) (bool, error) {
fs.acquire()
defer fs.release()
info, err := os.Stat(fs.toAbs(name)) info, err := os.Stat(fs.toAbs(name))
if err != nil { if err != nil {
return false, err return false, err
@ -227,8 +223,6 @@ func (fs *osFs) IsDir(name string) (bool, error) {
} }
func (fs *osFs) IsSymlink(name string) (bool, error) { func (fs *osFs) IsSymlink(name string) (bool, error) {
fs.acquire()
defer fs.release()
if info, err := os.Lstat(fs.toAbs(name)); err != nil { if info, err := os.Lstat(fs.toAbs(name)); err != nil {
return false, err return false, err
} else { } else {
@ -249,14 +243,10 @@ func (fs *osFs) glob(pattern string) ([]string, error) {
} }
func (fs *osFs) Lstat(path string) (stats os.FileInfo, err error) { func (fs *osFs) Lstat(path string) (stats os.FileInfo, err error) {
fs.acquire()
defer fs.release()
return os.Lstat(fs.toAbs(path)) return os.Lstat(fs.toAbs(path))
} }
func (fs *osFs) Stat(path string) (stats os.FileInfo, err error) { func (fs *osFs) Stat(path string) (stats os.FileInfo, err error) {
fs.acquire()
defer fs.release()
return os.Stat(fs.toAbs(path)) return os.Stat(fs.toAbs(path))
} }
@ -284,8 +274,6 @@ func (fs *osFs) ReadDirNames(name string) ([]string, error) {
} }
func (fs *osFs) Readlink(name string) (string, error) { func (fs *osFs) Readlink(name string) (string, error) {
fs.acquire()
defer fs.release()
return os.Readlink(fs.toAbs(name)) return os.Readlink(fs.toAbs(name))
} }