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| author | Jamie Liu <jamieliu@google.com> | 2019-06-06 17:20:43 -0700 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2019-06-06 17:22:00 -0700 |
| commit | 9ea248489b2144b4b477797ad744f500a9215dbc (patch) | |
| tree | a3fb9c5429bca8d136f9f433e5190902b08d204b /runsc/main.go | |
| parent | 315cf9a523d409dc6ddd5ce25f8f0315068ccc67 (diff) | |
Cap initial usermem.CopyStringIn buffer size.
Almost (?) all uses of CopyStringIn are via linux.copyInPath(), which
passes maxlen = linux.PATH_MAX = 4096. Pre-allocating a buffer of this
size is measurably inefficient in most cases: most paths will not be
this long, 4 KB is a lot of bytes to zero, and as of this writing the Go
runtime allocator maps only two 4 KB objects to each 8 KB span,
necessitating a call to runtime.mcache.refill() on ~every other call.
Limit the initial buffer size to 256 B instead, and geometrically
reallocate if necessary.
PiperOrigin-RevId: 251960441
Diffstat (limited to 'runsc/main.go')
0 files changed, 0 insertions, 0 deletions