Date: Sun, 2 Apr 2023 08:24:27 GMT From: Dmitry Chagin <dchagin@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 7f72324346ea - main - pseudofs: Microoptimize struct pfs_node Message-ID: <202304020824.3328ORl6076328@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by dchagin: URL: https://cgit.FreeBSD.org/src/commit/?id=7f72324346ea154a92671fc913dbe82c0287501a commit 7f72324346ea154a92671fc913dbe82c0287501a Author: Dmitry Chagin <dchagin@FreeBSD.org> AuthorDate: 2023-04-02 08:20:07 +0000 Commit: Dmitry Chagin <dchagin@FreeBSD.org> CommitDate: 2023-04-02 08:20:07 +0000 pseudofs: Microoptimize struct pfs_node Since 81167243b the size of struct pfs_node is 280 bytes, so the kernel memory allocator takes memory from 384 bytes sized bucket. However, the length of the node name is mostly short, e.g., for Linux emulation layer it is up to 16 bytes. The size of struct pfs_node w/o pfs_name is 152 bytes, i.e., we have 104 bytes left to fit the node name into the 256 bytes-sized bucket. Reviewed by: des Differential revision: https://reviews.freebsd.org/D39381 MFC after: 1 month --- sys/fs/pseudofs/pseudofs.c | 8 +++++--- sys/fs/pseudofs/pseudofs.h | 2 +- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/sys/fs/pseudofs/pseudofs.c b/sys/fs/pseudofs/pseudofs.c index 44473a926182..29071b34bd06 100644 --- a/sys/fs/pseudofs/pseudofs.c +++ b/sys/fs/pseudofs/pseudofs.c @@ -72,18 +72,20 @@ pfs_alloc_node_flags(struct pfs_info *pi, const char *name, pfs_type_t type, int { struct pfs_node *pn; int malloc_flags; + size_t len; - KASSERT(strlen(name) < PFS_NAMELEN, + len = strlen(name); + KASSERT(len < PFS_NAMELEN, ("%s(): node name is too long", __func__)); if (flags & PFS_NOWAIT) malloc_flags = M_NOWAIT | M_ZERO; else malloc_flags = M_WAITOK | M_ZERO; - pn = malloc(sizeof *pn, M_PFSNODES, malloc_flags); + pn = malloc(sizeof(*pn) + len + 1, M_PFSNODES, malloc_flags); if (pn == NULL) return (NULL); mtx_init(&pn->pn_mutex, "pfs_node", NULL, MTX_DEF | MTX_DUPOK); - strlcpy(pn->pn_name, name, sizeof pn->pn_name); + memcpy(pn->pn_name, name, len); pn->pn_type = type; pn->pn_info = pi; return (pn); diff --git a/sys/fs/pseudofs/pseudofs.h b/sys/fs/pseudofs/pseudofs.h index 158f74575e33..e355e5f5609f 100644 --- a/sys/fs/pseudofs/pseudofs.h +++ b/sys/fs/pseudofs/pseudofs.h @@ -219,7 +219,6 @@ struct pfs_info { * is not enforcable by WITNESS. */ struct pfs_node { - char pn_name[PFS_NAMELEN]; pfs_type_t pn_type; int pn_flags; struct mtx pn_mutex; @@ -240,6 +239,7 @@ struct pfs_node { struct pfs_node *pn_nodes; /* (o) */ struct pfs_node *pn_last_node; /* (o) */ struct pfs_node *pn_next; /* (p) */ + char pn_name[]; /* Keep it last */ }; /*
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202304020824.3328ORl6076328>