From 6f3229103e32c8c92c145921f863ba450d82d66f Mon Sep 17 00:00:00 2001 From: Chanyoung Park Date: Fri, 15 Aug 2025 18:06:18 +0000 Subject: [PATCH] crimson/.../rbm_device: remove unnecessary zero fill in anonymous mmap Anonymous mmap is zero-filled on first access by the kernel, so an explicit memset(0) is redundant and has been removed. Signed-off-by: Chanyoung Park --- .../os/seastore/random_block_manager/rbm_device.cc | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/src/crimson/os/seastore/random_block_manager/rbm_device.cc b/src/crimson/os/seastore/random_block_manager/rbm_device.cc index bc592d12bcbad..7cbd6ced39d16 100644 --- a/src/crimson/os/seastore/random_block_manager/rbm_device.cc +++ b/src/crimson/os/seastore/random_block_manager/rbm_device.cc @@ -206,16 +206,12 @@ open_ertr::future<> EphemeralRBMDevice::open( "Initializing test memory device {}", size); - void* addr = ::mmap( - nullptr, - size, - PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, - -1, - 0); + // memset 0 is not needed: anonymous mapping is zero-filled + void* addr = ::mmap(nullptr, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); buf = (char*)addr; - ::memset(buf, 0, size); return open_ertr::now(); } -- 2.39.5