From 59ed235c857692c427777465ad55f4157e0f44da Mon Sep 17 00:00:00 2001 From: Andreas Kling Date: Tue, 5 Nov 2019 19:35:12 +0100 Subject: Kernel: Implement O_DIRECT open() flag to bypass disk caches Files opened with O_DIRECT will now bypass the disk cache in read/write operations (though metadata operations will still hit the disk cache.) This will allow us to test actual disk performance instead of testing disk *cache* performance, if that's what we want. :^) There's room for improvment here, we're very aggressively flushing any dirty cache entries for the specific block before reading/writing that block. This is done by walking the entire cache, which may be slow. --- Kernel/FileSystem/VirtualFileSystem.h | 1 + 1 file changed, 1 insertion(+) (limited to 'Kernel/FileSystem/VirtualFileSystem.h') diff --git a/Kernel/FileSystem/VirtualFileSystem.h b/Kernel/FileSystem/VirtualFileSystem.h index 588e1d85f5..cd1b919012 100644 --- a/Kernel/FileSystem/VirtualFileSystem.h +++ b/Kernel/FileSystem/VirtualFileSystem.h @@ -24,6 +24,7 @@ #define O_DIRECTORY 00200000 #define O_NOFOLLOW 00400000 #define O_CLOEXEC 02000000 +#define O_DIRECT 04000000 #define O_NOFOLLOW_NOERROR 0x4000000 class Custody; -- cgit v1.2.3