On 2024/10/18 02:06, Jann Horn wrote:
On Thu, Oct 17, 2024 at 11:48 AM Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> wrote:
In preparation for reclaiming empty PTE pages, this commit first makes
zap_pte_range() to handle the full within-PMD range, so that we can more
easily detect and free PTE pages in this function in subsequent commits.
I think your patch causes some unintended difference in behavior:
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
mm/memory.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index caa6ed0a7fe5b..fd57c0f49fce2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1602,6 +1602,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
swp_entry_t entry;
int nr;
+retry:
This "retry" label is below the line "bool force_flush = false,
force_break = false;", so I think after force_break is set once and
you go through the retry path, every subsequent present PTE will again
bail out and retry. I think that doesn't lead to anything bad, but it
seems unintended.
Right, thanks for catching this! Will set force_flush and force_break to
false under "retry" label in v2.
Thanks!
