slru bank
Hello all,
This PostgreSQL version is 17beta2.
In SlruSelectLRUPage(), Why do we need to traverse all slots to find that a page already has a buffer assigned? Why not find it
from the [bankstart,bankend]?
Best regards
On Thu, Aug 22, 2024 at 7:07 PM 席冲(宜穆) <xichong.xc@alibaba-inc.com> wrote:
In SlruSelectLRUPage(), Why do we need to traverse all slots to find that
a page already has a buffer assigned? Why not find it
from the [bankstart,bankend]?
Only the bank is searched, both of the logic loops are bounded by:
for (int slotno = bankstart; slotno < bankend; slotno++)
David J.
"David G. Johnston" <david.g.johnston@gmail.com> writes:
On Thu, Aug 22, 2024 at 7:07 PM 席冲(宜穆) <xichong.xc@alibaba-inc.com> wrote:
In SlruSelectLRUPage(), Why do we need to traverse all slots to find that
a page already has a buffer assigned? Why not find it
from the [bankstart,bankend]?
Only the bank is searched, both of the logic loops are bounded by:
for (int slotno = bankstart; slotno < bankend; slotno++)
I think the OP has rediscovered the bug already fixed in 7b063ff26.
That's post-17beta2, though.
regards, tom lane
On Thu, Aug 22, 2024 at 7:27 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
"David G. Johnston" <david.g.johnston@gmail.com> writes:
On Thu, Aug 22, 2024 at 7:07 PM 席冲(宜穆) <xichong.xc@alibaba-inc.com>
wrote:
In SlruSelectLRUPage(), Why do we need to traverse all slots to find
that
a page already has a buffer assigned? Why not find it
from the [bankstart,bankend]?Only the bank is searched, both of the logic loops are bounded by:
for (int slotno = bankstart; slotno < bankend; slotno++)I think the OP has rediscovered the bug already fixed in 7b063ff26.
That's post-17beta2, though.
Indeed. I was looking at HEAD.
David J.