5.4-stable review patch. If anyone has any objections, please let me know.
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From: Guangguan Wang guangguan.wang@linux.alibaba.com
[ Upstream commit 3ac14b9dfbd345e891d48d89f6c2fa519848f0f4 ]
SG_MAX_SINGLE_ALLOC is used to limit maximum number of entries that will be allocated in one piece of scatterlist. When the entries of scatterlist exceeds SG_MAX_SINGLE_ALLOC, sg chain will be used. From commit 7c703e54cc71 ("arch: switch the default on ARCH_HAS_SG_CHAIN"), we can know that the macro CONFIG_ARCH_NO_SG_CHAIN is used to identify whether sg chain is supported. So, SMC-R's rmb buffer should be limited by SG_MAX_SINGLE_ALLOC only when the macro CONFIG_ARCH_NO_SG_CHAIN is defined.
Fixes: a3fe3d01bd0d ("net/smc: introduce sg-logic for RMBs") Signed-off-by: Guangguan Wang guangguan.wang@linux.alibaba.com Co-developed-by: Wen Gu guwen@linux.alibaba.com Signed-off-by: Wen Gu guwen@linux.alibaba.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/smc/smc_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index fb3543f7f278e..0a1520c75b862 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -691,7 +691,6 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) */ static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb) { - const unsigned int max_scat = SG_MAX_SINGLE_ALLOC * PAGE_SIZE; u8 compressed;
if (size <= SMC_BUF_MIN_SIZE) @@ -701,9 +700,11 @@ static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb) compressed = min_t(u8, ilog2(size) + 1, is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
+#ifdef CONFIG_ARCH_NO_SG_CHAIN if (!is_smcd && is_rmb) /* RMBs are backed by & limited to max size of scatterlists */ - compressed = min_t(u8, compressed, ilog2(max_scat >> 14)); + compressed = min_t(u8, compressed, ilog2((SG_MAX_SINGLE_ALLOC * PAGE_SIZE) >> 14)); +#endif
return compressed; }