From da2e46dff6576c29fa1d379c943bb7943aa6e7ce Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 21 Feb 2020 15:25:37 +0100 Subject: [PATCH] ash: memalloc: Avoid looping in growstackto Upstream commit: Date: Thu, 31 May 2018 01:51:48 +0800 memalloc: Avoid looping in growstackto Currently growstackto will repeatedly call growstackblock until the requisite size is obtained. This is wasteful. This patch changes growstackblock to take a minimum size instead. Signed-off-by: Herbert Xu Signed-off-by: Denys Vlasenko --- shell/ash.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/shell/ash.c b/shell/ash.c index fd2fc9f23..8d1822847 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -1678,15 +1678,16 @@ popstackmark(struct stackmark *mark) * part of the block that has been used. */ static void -growstackblock(void) +growstackblock(size_t min) { size_t newlen; newlen = g_stacknleft * 2; if (newlen < g_stacknleft) ash_msg_and_raise_error(bb_msg_memory_exhausted); - if (newlen < 128) - newlen += 128; + min = SHELL_ALIGN(min | 128); + if (newlen < min) + newlen += min; if (g_stacknxt == g_stackp->space && g_stackp != &stackbase) { struct stack_block *sp; @@ -1736,16 +1737,15 @@ static void * growstackstr(void) { size_t len = stackblocksize(); - growstackblock(); + growstackblock(0); return (char *)stackblock() + len; } static char * growstackto(size_t len) { - while (stackblocksize() < len) - growstackblock(); - + if (stackblocksize() < len) + growstackblock(len); return stackblock(); } -- 2.25.1