Re: Remove the limit on the number of entries allowed in
От | Simon Riggs |
---|---|
Тема | Re: Remove the limit on the number of entries allowed in |
Дата | |
Msg-id | 1150392031.2587.10.camel@localhost.localdomain обсуждение исходный текст |
Ответ на | Re: Remove the limit on the number of entries allowed in catcaches, ("Qingqing Zhou" <zhouqq@cs.toronto.edu>) |
Ответы |
Re: Remove the limit on the number of entries allowed in catcaches,
|
Список | pgsql-hackers |
On Thu, 2006-06-15 at 17:50 +0800, Qingqing Zhou wrote: > "Simon Riggs" <simon@2ndquadrant.com> wrote > > > > Can we do the same for the file descriptors in fd.c? > > > > Very often the total number of file descriptors is much less than the > > maximum, so it would make sense to only maintain the LRU when we are > > using more than 50%-75% of the maximum. > > > > I am not against doing it but AFAIR the LRU file operations is > (1) not frequent; The LRU moves each time we do FileRead or FileWrite, not just on open/close operations. > (2) the cost is only several CPU circles if we do not run out of > fds; So its not really likely ever to show high on oprofile, but if its an avoidable operation that isn't always needed, why do it? > (3) the LRU lseek/close/open big cost is still not avoidable when we > really run out of fds. Agreed, but the limit is reasonably high, so this isn't anywhere near being something we always hit otherwise we would be more worried. -- Simon Riggs EnterpriseDB http://www.enterprisedb.com
В списке pgsql-hackers по дате отправления: