[PATCH] 9p: Use kvmalloc for message buffers
From: Pierre Barre
Date: Wed Jul 30 2025 - 11:08:38 EST
While developing a 9P server (https://github.com/Barre/ZeroFS) and testing it under high-load, I was running into allocation failures. The failures occur even with plenty of free memory available because kmalloc requires contiguous physical memory.
This results in errors like:
ls: page allocation failure: order:7, mode:0x40c40(GFP_NOFS|__GFP_COMP)
Signed-off-by: Pierre Barre <pierre@xxxxxxxx>
---
net/9p/client.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/9p/client.c b/net/9p/client.c
index 5c1ca57ccd28..f82b5674057c 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -230,7 +230,7 @@ static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
fc->cache = c->fcall_cache;
} else {
- fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
+ fc->sdata = kvmalloc(alloc_msize, GFP_NOFS);
fc->cache = NULL;
}
if (!fc->sdata)
@@ -252,7 +252,7 @@ void p9_fcall_fini(struct p9_fcall *fc)
if (fc->cache)
kmem_cache_free(fc->cache, fc->sdata);
else
- kfree(fc->sdata);
+ kvfree(fc->sdata);
}
EXPORT_SYMBOL(p9_fcall_fini);
--
2.39.5 (Apple Git-154)